scholarly journals Survival probabilities of first and second clutches of blackbird (Turdus merula) in an urban environment

2010 ◽  
Vol 62 (2) ◽  
pp. 489-493 ◽  
Author(s):  
Kornelia Kurucz ◽  
Helena Kallenberger ◽  
Csilla Szigeti ◽  
J.J. Purger
Keyword(s):  
Urban Environment ◽  
Small Mammals ◽  
Breeding Success ◽  
Survival Probability ◽  
Botanical Garden ◽  
Hedera Helix ◽  
Artificial Nests ◽  
The Difference ◽  
The University ◽  
Predation Rates

The breeding success of blackbirds was investigated in April and June 2008 and 2009 in the Botanical Garden of the University of Pecs, with a total of 50 artificial nests at each of the four sessions (with 1 quail egg and 1 plasticine egg placed in every nest). In all four study periods of the two years, 2 nests (4%) were destroyed by predators. Six nests (12%, of the nests) were not discovered in either of the cases. The survival probability of artificial nests was greater in April than in June (both years), but the difference was significant only in 2008. Nests placed into a curtain of ivy (Hedera helix) on a wall were located higher up than those in bushes, yet their predation rates were quite similar. The predation values of quail vs. plasticine eggs did not differ in 2008. In the year 2009, however, significantly more quail eggs were discovered (mostly removed), than plasticine eggs. Marks that were left on plasticine eggs originated mostly from small mammals and small-bodied birds, but the disappearance of a large number of quail and plasticine eggs was probably caused by larger birds, primarily jays.

Predation rates of artificial nests in the edge and interior of a southern Victorian forest

2002 ◽  
Vol 29 (4) ◽  
pp. 341 ◽  
Author(s):  
Lainie Berry
Keyword(s):  
Small Mammals ◽  
Nest Predation ◽  
Forest Edge ◽  
Forest Edges ◽  
Artificial Nests ◽  
Avian Predators ◽  
Forest Interior ◽  
Grey Shrike ◽  
Predation Rates

Predation rates of nests at human-induced habitat edges may be greater than in forest interior due to differences in predator assemblages and predator activity. I compared the predation rates on 192 artificial nests containing plasticine eggs placed in forest edge and interior sites at Bunyip State Park, Victoria. The nest-predation rates at the forest edge sites were significantly greater (mean = 52–58%) than that at the forest interior sites (mean = 30–39%). The relative rates of predation by birds compared with mammals were significantly greater at forest edge sites (mean = 78–94%) than at forest interior sites (mean = 36–67%). Higher rates of nest predation at forest edges appeared to be due to greater densities of avian predators such as the grey shrike-thrush (Colluricincla harmonica), and/or lower abundances of small mammals. However, biases towards certain predator types may mask real, or create false, patterns in predation rates of artificial nests. A better understanding of how predators respond to artificial nests compared with natural nests is required. Until then, results of predation studies that use artificial nests should be interpreted with caution.

Predation on artificial ground nests in relation to abundance of rodents in two types of forest habitats in the Tatra Mountains (southern Poland)

2019 ◽  
Vol 46 (3) ◽  
pp. 205
Author(s):  
Marcin Matysek ◽  
Karol Zub ◽  
Robert Gwiazda ◽  
Filip Zięba ◽  
Maciej Klimecki ◽  
...  
Keyword(s):  
Small Mammals ◽  
Breeding Success ◽  
Myodes Glareolus ◽  
Alternative Prey ◽  
Tatra Mountains ◽  
Forest Habitat ◽  
Artificial Nests ◽  
The Tatra Mountains ◽  
Forest Habitats ◽  
Ground Nesting

Context The breeding success of ground-nesting birds is strongly related to the predation rate. Many predators feed primarily on rodents when the densities of rodents are high and change to alternative prey (eggs or young birds) when the main prey populations decrease. Aims During a 3-year study, predation on an artificial nest was related to population dynamics of small mammals in coniferous and deciduous forests in the Tatra Mountains (western Carpathians). Methods Small mammals were captured using the live traps. In deciduous forest habitats, we placed 36 traps and, in coniferous forest habitats, we placed 18 traps. In total, 174 artificial nests imitating broods of hazel grouse (Tetrastes bonansia) were located randomly in both types of forest habitat between 2012 and 2014. Predators of the artificial nests were identified by camera-traps at 87 nests. Key results Most of the artificial nests were lost to predation by mammals. The most numerous species of rodents in both types of forest habitat were the yellow-necked mouse (Apodemus flavicollis) and the bank vole (Myodes glareolus). A significant decrease in the number of rodents was followed by a considerable increase of predation on artificial nests. There were no significant differences in the rates of predation between the two forest-habitat types. Conclusions Our results support the alternative prey hypothesis and suggest that the breeding success of ground-nesting birds in the forests of the Tatra Mountains varies strongly from year to year, depending on the abundance of rodents. Implications Increasing of rodents’ density may result in lower predation pressure on eggs of ground-nesting birds. This finding may help modify recommendations for conservationists and forest managers to optimize their effort to save populations of Galliformes.

16th and 17th Workshops of the International Association of Vegetation Science Working Group for the European Vegetation Survey (Rome, Italy, 22-26 March 2007; Brno, Czech Republic, 1-5 May 2008)

2008 ◽  
pp. 131-133
Author(s):  
T. M. Lysenko ◽  
Yu. A. Semenishchenkov
Keyword(s):  
Czech Republic ◽  
Working Group ◽  
International Association ◽  
Botanical Garden ◽  
European Countries ◽  
Vegetation Survey ◽  
Vegetation Science ◽  
The University ◽  
Science Working

22-26 March 2007 in Rome (Italy), in the Botanical garden of the University «La Sapienza» hosted the 16th meeting of the Working group «Review of the Vegetation of Europe» of the International Association of Vegetation Science (IAVS). These meetings are held every spring in one of the European countries and dedicated to various topics.

scholarly journals Enamel interproximal reduction during treatment with clear aligners: digital planning versus OrthoCAD analysis

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Giuseppina Laganà ◽  
Arianna Malara ◽  
Roberta Lione ◽  
Carlotta Danesi ◽  
Simonetta Meuli ◽  
...  
Keyword(s):  
Treatment Plan ◽  
End Of Treatment ◽  
The Mean ◽  
The Difference ◽  
Dependent Sample ◽  
University Of Rome ◽  
The University ◽  
Enamel Reduction ◽  
Lower Arch

Abstract Background The aim of the study was to compare the amount of interproximal enamel reduction (IPR) provided on ClinCheck software with the amount of IPR carried out by the orthodontist during treatment with clear aligners. Methods 30 subjects (14 males, 16 females; mean age of 24.53 ± 13.41 years) randomly recruited from the Invisalign account of the Department of Orthodontics at the University of Rome “Tor Vergata” from November 2018 to October 2019, were collected according to the following inclusion criteria: mild to moderate dento-alveolar discrepancy (1.5–6.5 mm); Class I canine and molar relationship; full permanent dentition (excluding third molars); both arches treated only using Comprehensive Package by Invisalign system; treatment plan including IPR. Pre- (T0) and post-treatment (T1) digital models (.stl files), created from an iTero scan, were collected from all selected patients. The OrthoCAD digital software was used to measure tooth mesiodistal width in upper and lower arches before (T0) and at the end of treatment (T1) before any refinement. The widest mesio-distal diameter was measured for each tooth excluding molars by “Diagnostic” OrthoCAD tool. The total amount of IPR performed during treatment was obtained comparing the sum of mesio-distal widths of all measured teeth at T0 and T1. Significant T1–T0 differences were tested with dependent sample t-test (P < 0.05). Results In the upper arch, IPR was digitally planned on average for 0.62 mm while in the lower arch was on average for 1.92 mm. As for the amount of enamel actually removed after IPR performing, it was on average 0.62 mm in the maxillary arch. In the mandibular arch, the mean of IPR carried out was 1.93 mm. The difference between planned IPR and performed IPR is described: this difference was on average 0.00 mm in the upper arch and 0.01 in the lower arch. Conclusions The amount of enamel removed in vivo corresponded with the amount of IPR planned by the Orthodontist using ClinCheck software.

scholarly journals Determination of Force Coefficients for a Submerged Rigid Breakwater under the Action of Solitary Waves

Water ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 315
Author(s):  
Francesco Aristodemo ◽  
Giuseppe Tripepi ◽  
Luana Gurnari ◽  
Pasquale Filianoti
Keyword(s):  
Solitary Waves ◽  
Pressure Sensors ◽  
Wave Forces ◽  
Wave Loads ◽  
Force Coefficients ◽  
Wave Flume ◽  
Physical Tests ◽  
The Difference ◽  
The University ◽  
Semi Empirical

We present an analysis related to the evaluation of Morison and transverse force coefficients in the case of a submerged square barrier subject to the action of solitary waves. To this purpose, two-dimensional experimental research was undertaken in the wave flume of the University of Calabria, in which a rigid square barrier was provided by a discrete battery of pressure sensors to determine the horizontal and vertical hydrodynamic forces. A total set of 18 laboratory tests was carried out by varying the motion law of a piston-type paddle. Owing to the low Keulegan–Carpenter numbers of the tests, the force regime of the physical tests was defined by the dominance of the inertia loads in the horizontal direction and of the lift loads in the vertical one. Through the use of the time series of wave forces and the undisturbed kinematics, drag, horizontal inertia, lift, and vertical inertia coefficients in the Morison and transverse semi-empirical schemes were calculated using time-domain approaches, adopting the WLS1 method for the minimization of the difference between the maximum forces and the linked phase shifts by comparing laboratory and calculated wave loads. Practical equations to calculate these coefficients as a function of the wave non-linearity were introduced. The obtained results highlighted the prevalence of the horizontal forces in comparison with the vertical ones which, however, prove to be fundamental for stability purposes of the barrier. An overall good agreement between the experimental forces and those calculated by the calibrated semi-empirical schemes was found, particularly for the positive horizontal and vertical loads. The analysis of the hydrodynamic coefficients showed a decreasing trend for the drag, horizontal inertia, and lift coefficients as a function of the wave non-linearity, while the vertical inertia coefficient underlined an initial increasing trend and a successive slight decreasing trend.

scholarly journals Do Repugnant Scents Increase Survival of Ground Nests? A Test with Artificial and Natural Duck Nests

2007 ◽  
Vol 121 (2) ◽  
pp. 150
Author(s):  
Vanessa B. Harriman ◽  
Justin A. Pitt ◽  
Serge Larivière
Keyword(s):  
Human Hair ◽  
Nest Predation ◽  
Survival Rates ◽  
Olfactory Cues ◽  
Artificial Nests ◽  
Treatment Groups ◽  
Mammalian Predators ◽  
High Predation ◽  
Ground Nesting ◽  
Predation Rates

Ground-nesting birds typically experience high predation rates on their nests, often by mammalian predators. As such, researchers and wildlife managers have employed numerous techniques to mitigate nest predation. We investigated the use of scents as repellents to deter predators from both artificial and natural ground nests. Survival rates of artificial nests did not differ among six groups of substances (Wald ?2 df = 5 = 4.53, P < 0.48); however the chronology of predation among groups differed. A commercial Coyote urine based deterrent (DEER-D-TERTM), human hair, and Worcestershire sauce were depredated faster than the control (F4,5 = 40.3, P < 0.001). Nest survival of natural nests differed among those groups tested (Wald ?2 df = 2 = 11.8, P < 0.005); the eight mothball treatment decreased survival (Wald ?2 df = 1 = 11.5, P < 0.005), which indicated that novel smells may attract predators or result in duck nest abandonment when coupled with natural duck scent. Chronologies of predation events among treatment groups were not different for natural nests (F2,3 = 1.9, P = 0.22). These findings indicate an interaction between novel scents and predator olfactory cues.

scholarly journals XXIII.—On the Disruptive Discharge of Electricity: An Experimental Thesis for the Degree of Doctor of Science, Department A

1878 ◽  
Vol 28 (2) ◽  
pp. 633-671 ◽  
Author(s):  
Alexander Macfarlane
Keyword(s):  
Copper Wire ◽  
Late Summer ◽  
The Other ◽  
Straight Line ◽  
Summer Session ◽  
The Difference ◽  
A Chain ◽  
The One ◽  
Metallic Parts ◽  
The University

The experiments to which I shall refer were carried out in the physical laboratory of the University during the late summer session. I was ably assisted in conducting the experiments by three students of the laboratory,—Messrs H. A. Salvesen, G. M. Connor, and D. E. Stewart. The method which was used of measuring the difference of potential required to produce a disruptive discharge of electricity under given conditions, is that described in a paper communicated to the Royal Society of Edinburgh in 1876 in the names of Mr J. A. Paton, M. A., and myself, and was suggested to me by Professor Tait as a means of attacking the experimental problems mentioned below.The above sketch which I took of the apparatus in situ may facilitate tha description of the method. The receiver of an air-pump, having a rod capable of being moved air-tight up and down through the neck, was attached to one of the conductors of a Holtz machine in such a manner that the conductor of the machine and the rod formed one conducting system. Projecting from the bottom of the receiver was a short metallic rod, forming one conductor with the metallic parts of the air-pump, and by means of a chain with the uninsulated conductor of the Holtz machine. Brass balls and discs of various sizes were made to order, capable of being screwed on to the ends of the rods. On the table, and at a distance of about six feet from the receiver, was a stand supporting two insulated brass balls, the one fixed, the other having one degree of freedom, viz., of moving in a straight line in the plane of the table. The fixed insulated ball A was made one conductor with the insulated conductor of the Holtz and the rod of the receiver, by means of a copper wire insulated with gutta percha, having one end stuck firmly into a hole in the collar of the receiver, and having the other fitted in between the glass stem and the hollow in the ball, by which it fitted on to the stem tightly. A thin wire similarly fitted in between the ball B and its insulating stem connected the ball with the insulated half ring of a divided ring reflecting electrometer.

scholarly journals Family Climate Patterns and Its Relationship with Self-Concept among Students at the University of Islamic Sciences in light of the Variables of Gender and Age

2017 ◽  
Vol 9 (1) ◽  
pp. 145
Author(s):  
Fatima Mohammad Rashed Al Talahin ◽  
Hana Khaled Al –Raqqad ◽  
Eman Saeed Al- Bourini ◽  
Bilal Adel Al-Kateeb
Keyword(s):  
Pearson Correlation ◽  
Statistical Significance ◽  
Self Concept ◽  
Family Climate ◽  
Gender And Age ◽  
Climate Patterns ◽  
The Difference ◽  
The University ◽  
The Impact ◽  
The Relationship

The aim of this study is to clarify the relationship between self-concept and patterns of family climate among students at the University of Islamic Sciences, and also aimed to investigate the effect of gender and age on this relationship.The sample of the study consisted of a group of students were selected randomly, totaling (139) students; (58) male and (81) female students.Two questionnaires were distributed on 139 students. The first questionnaire was on the impact of patterns of family climate on self-concept and the second one about self-concept. Then the researcher analyzed the results of each item in the questionnaire using appropriated statistical methods, calculated the correlation between self-concept and patterns of family climate using the Pearson correlation coefficient, and G-test to find the difference between correlation coefficients.The results showed a positive statistical significance relationship between family climate patterns on one hand and between self-concept in all its dimensions on the other hand.

Twelfth-century Cosmography, theDe secretis philosophie, and Māshā'allāh (Attr. to),Liber de Orbe

Traditio ◽  
2012 ◽  
Vol 67 ◽  
pp. 235-276
Author(s):  
Barbara Obrist
Keyword(s):  
New York ◽  
Thirteenth Century ◽  
Natural Philosophy ◽  
Lunar Eclipse ◽  
Latin Text ◽  
Central Section ◽  
The Difference ◽  
The University ◽  
University Of Manchester ◽  
The Universe

TheLiber de orbe, attributed to Māshā'allāh (fl. 762–ca. 815) in the list of Gerard of Cremona's translations, stands out as one of the few identifiable sources for the indirect knowledge of Peripatetic physics and cosmology at the very time Aristotle's works on natural philosophy themselves were translated into Latin, from the 1130s onward. This physics is expounded in an opening series of chapters on the bodily constitution of the universe, while the central section of the treatise covers astronomical subjects, and the remaining parts deal with meteorology and the vegetal realm. Assuming that Gerard of Cremona's translation of theLiber de orbecorresponds to the twenty-seven chapter version that circulated especially during the thirteenth and fourteenth centuries, it was, however, not this version, but a forty-chapter expansion thereof that became influential as early as the 1140s. It may have originated in Spain, as indicated, among others, by a reference to the difference of visibility of a lunar eclipse between Spain and Mecca. Unlike the twenty-seven chapterLiber de orbe, this expanded and also partly modified text remains in manuscript, and none of the three copies known so far gives a title or mentions Māshā'allāh as an author. Instead, the thirteenth-century witness that is now in New York attributes the work to an Alcantarus:Explicit liber Alcantari Caldeorum philosophi. While no Arabic original of the twenty-seven chapterLiber de orbehas come to light yet, Taro Mimura of the University of Manchester recently identified a manuscript that partly corresponds to the forty-chapter Latin text, as well as a shorter version thereof.

LACTATION PERFORMANCE OF RANGE BEEF AND DAIRY-BEEF COWS

1984 ◽  
Vol 64 (2) ◽  
pp. 253-265 ◽  
Author(s):  
SARAH BUTSON ◽  
R. T. BERG
Keyword(s):  
Milk Production ◽  
Beef Cows ◽  
Significant Decline ◽  
Lactation Performance ◽  
University Of Alberta ◽  
Brown Swiss ◽  
Percent Protein ◽  
The Difference ◽  
The University ◽  
Better Than

A milking experiment with range, single-suckled beef cows was conducted over two lactations in 1976 and 1977 at the University of Alberta Research Ranch. A total of 428 cows were milked, ranging from 2 to 10 yr of age and representing four breed groups of Herefords and crossbreds of traditional beef and dairy breeds. Measurements of milk were taken in June and September each year. Milk was extracted following an intrajugular injection of 20 IU of oxytocin. Samples were analyzed for butterfat percent, protein percent and lactose percent. Age and breed of dam differences in milk yields, constituent percentages and yields were assessed. Least squares means of yields pooled over the two periods each year indicated that dams with Holstein and Brown Swiss breeding (DS) yielded more milk than beef crossbreds and purebred Herefords. Average milk yields estimated over 24 h ranged from 5.7 kg/day for Herefords to 7.8 kg/day for DS dams. Compared to 2-yr olds at 100%, 3-yr olds produced 125%, 4-yr olds 136% and mature cows 139% greater yield. The difference between June and September yields was evident between breed groups. Hereford milk production exhibited the greatest decline over 87 days compared to all other crossbreds and DS were the most persistent. Mature cows maintained milk yields better than younger cows, and 2-yr old milk yields declined most noticeably. All crossbred groups produced less butterfat percent and lactose percent content than the Herefords, yet yielded more total energy. All constituent percentages were higher than those reported for commercial dairy cattle. All constituent percentages increased significantly from June to September at approximately 130 days in lactation. A significant decline was noted for all constituent yields in September. Dairy crossbreds demonstrated the highest persistency for all constituent yields. Beef Synthetic dams were intermediate in yield persistency. Average milk yields had negative (P < 0.05) correlations with average constituent percentages. Inter-correlations among constituent percentages were variable and generally small and negative. Key words: Lactation, range cows

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