scholarly journals Breeding performance in captivity of meadow voles (Microtus pennsylvanicus) from decline- and increase-phase populations

1992 ◽  
Vol 70 (8) ◽  
pp. 1561-1566 ◽  
Author(s):  
Steve Mihok ◽  
Rudy Boonstra
Keyword(s):  
Prior Experience ◽  
Microtus Pennsylvanicus ◽  
Small Field ◽  
Breeding Performance ◽  
Meadow Voles ◽  
Decline Phase ◽  
The Poor ◽  
In Captivity ◽  
Two Generations

A major enigma in understanding microtine cycles is the failure of decline-phase animals to increase. We compared the performance of wild-caught meadow voles and their progeny from Pinawa, Manitoba, collected from a decline year (1985) with that of animals from an increase year (1986) by breeding them in the laboratory in Pinawa (animals from both years) and in the field and laboratory in Toronto (only F1 and F2 animals from 1985). Overall only 35% of the 1985 females or their progeny bred in the laboratory in Pinawa compared with 100% of the 1986 females. The interval between pairing with a male and birth of litters was 2–7 months for the 1985 females compared with 3–4 weeks for the 1986 females. The poor breeding performance of 1985 females occurred only in the laboratory; in small field enclosures in Toronto all F1 and F2 females conceived and had litters within 3–4 weeks. In contrast, 1985 males readily sired litters either with 1986 females in the laboratory or with Toronto females in the field. We conclude that the prior experience of decline-phase females had long-term detrimental consequences for the performance of the first two generations under laboratory conditions.

Control of Small Mammals on a Hardwood Plantation by Poison-Bait Feeders

1977 ◽  
Vol 53 (2) ◽  
pp. 96-99
Author(s):  
Arthur M. Martell ◽  
Andrew Radvanyi
Keyword(s):  
Small Mammals ◽  
Microtus Pennsylvanicus ◽  
Meadow Vole ◽  
Low Density ◽  
Meadow Voles ◽  
Southern Ontario

Poison-bait feeder stations were placed on a hardwood plantation in southern Ontario in 1973 to attempt long-term control of a meadow vole (Microtus pennsylvanicus) population by continuous dispensing of poisoned grain. Baiting by means of feeders successfully reduced the numbers of meadow voles and maintained them at a low density, about 3-6/ha (1.2-2.4/acre), through April 1976. During the same period, the density of meadow voles on surrounding unpoisoned areas declined from a 1973 peak to about the same as that found on the poisoned plot by fall and winter 1975-76. Despite that low density, less than 4/ha (1.6/acre), severe gnawing and girdling of young hardwoods occurred during winter. Poison-bait feeders are efficient at reducing meadow vole populations from high to low density, but it cannot be assumed that even those low-density populations will not damage hardwood plantations.

Long-term effects of malnutrition on reproduction: a laboratory study with meadow voles, Microtus pennsylvanicus, and red-backed voles, Clethrionomys gapperi

1994 ◽  
Vol 72 (2) ◽  
pp. 232-238 ◽  
Author(s):  
Søren Bondrup-Nielsen ◽  
Peter M. Foley
Keyword(s):  
Microtus Pennsylvanicus ◽  
Clethrionomys Gapperi ◽  
Long Term Effects ◽  
Meadow Voles ◽  
Experimental Animals ◽  
Behavioural Effects ◽  
Ecological Implications ◽  
Catch Up ◽  
Growth And Reproduction

Infant malnutrition has long-term behavioural effects. We determined the long-term effects of infant malnutrition on reproduction in meadow voles (Microtus pennsylvanicus) and red-backed voles (Clethrionomys gapperi). Experimental animals received standard diets diluted with cornstarch (2:1) during a combination of the following periods: gestation, lactation, and for 3 weeks postweaning. Growth and reproduction of these animals were compared with those of control individuals. During the administration of starch-diluted diets growth was retarded but subjects experienced "catch-up" once they were put on normal diets. Effects on reproduction of individuals that had experienced malnutrition as infants were minimal. Litter size was greater (both species), the proportion of females reproducing was greater (meadow voles), and birth mass was greater (meadow voles), but the growth rate of offspring was slightly lower (both species), for females malnourished as infants. The ecological implications of infant malnutrition are discussed.

Long-term effects of infant malnutrition on the behaviour of adult meadow voles, Microtus pennsylvanicus

1992 ◽  
Vol 70 (7) ◽  
pp. 1304-1308 ◽  
Author(s):  
Kim Lee Wong ◽  
Søren Bondrup-Nielsen
Keyword(s):  
Microtus Pennsylvanicus ◽  
Standard Diet ◽  
Activity Levels ◽  
Long Term Effects ◽  
Meadow Voles ◽  
Pup Retrieval ◽  
Cumulative Duration ◽  
And Control ◽  
Poor Nutrition

Several studies on laboratory mice and rats have shown that malnutrition during infancy has a variety of long-term effects extending into adulthood. These effects are manifested in reproduction, including reduced litter sizes, reduced growth rates of the young, and skewed sex ratios, and in behaviour, including increased nervousness, decreased problem-solving ability, and reduced pup retrieval to the nest by the mother. This study investigated the effects of early malnutrition on behaviour in adult meadow voles, Microtus pennsylvanicus. Experimental animals received a standard diet diluted with pure cornstarch (1 part standard diet to 2 parts pure cornstarch) through their mothers during lactation and directly for 3 weeks postweaning. Control individuals always received the standard diet ad libitum. The cumulative duration of 13 behaviours was measured in 10-min trial periods and compared between experimental and control animals. Experimental females differed from control females in a number of behaviours, especially those involving high activity levels, whereas experimental and control males showed little difference in the behaviours performed. The behaviour profile of previously malnourished females was similar to those of both control and experimental males. Increased activity, resulting from poor nutrition, may have consequences for dispersal and spacing behaviour.

ANALYSIS OF ABDOMINAL TYPHOID INCIDENCE IN THE SOUTH REGION OF THE KYRGYZ REPUBLIC

2020 ◽  
pp. 43-48
Author(s):  
Zakirova J.S. ◽  
Nadirbekova R.A. ◽  
Zholdoshev S.T.
Keyword(s):  
Drinking Water ◽  
Typhoid Fever ◽  
Risk Groups ◽  
The Body ◽  
Kyrgyz Republic ◽  
Radiation Factor ◽  
High Quality ◽  
Two Generations ◽  
Immunological Deficiency

The article analyze the long-term morbidity, spread of typhoid fever in the southern regions of the Kyrgyz republic, and remains a permanent epidemic focus in the Jalal-Abad region, where against the low availability of the population to high-quality drinking water, an additional factor on the body for more than two generations and radiation factor, which we confirmed by the spread among the inhabitants of Mailuu-Suu of nosological forms of the syndrome of immunological deficiency, as a predictor of risk groups for infectious diseases, including typhoid fever.

Percepción de la Población Pobre de Santiago sobre el Mercado Laboral en Chile al año 2011 y evolución desde el año 2003

Oikos ◽  
2015 ◽  
Vol 15 (31) ◽  
pp. 153
Author(s):  
Marcelo Yáñez Pérez
Keyword(s):  
Social Capital ◽  
Labor Market ◽  
Equal Opportunities ◽  
Capital Social ◽  
Union Power ◽  
Family Labor ◽  
The Poor ◽  
State Unemployment ◽  
Poor Population

RESUMENEl artículo muestra los principales resultados de la investigación Percepción de la Población Pobre de Santiago sobre el Mercado Laboral en Chile, realizada durante 9 años consecutivos desde 2003, por la Escuela de Administración y Economía de la Universidad Católica Silva Henríquez. El estudio incluye antecedentes sobre las concepciones de empleo y desempleo de este grupo de la población, así como la identificación de quienes –a su juicio– serían los responsables de que las personas pobres obtengan un trabajo y la calificación que le asignan a su gestión. También contempla sus percepciones en torno al apoyo del Estado, nivel de desempleo, influencia del capital social, respeto por los trabajadores, igualdad de oportunidades, poder de los sindicatos, entre otros aspectos, además del nivel de desempleo familiar y tipo de problemas laborales que han enfrentado.Palabras clave: mercado laboral, pobreza, percepciones, equidad.Este estudio ha sido realizado en el contexto de la investigación “Percepción de la población pobre de Santiago sobre las condiciones de acceso, equidad y satisfacción en la obtención de bienes básicos y públicos – año 2011: visión evolutiva desde el año 2003”, que es parte del Programa de Investigación de la Escuela de Administración y Economía de la UCSH. Esta investigación ha sido financiada desde sus inicios y en su totalidad con fondos propios de esta Universidad.Perception of the Poor Population from Santiago of The Labor Market in Chile in the year 2011 and evolution from 2003ABSTRACTThe paper shows the main results of a long-term investigation on the perceptions of the poor of Santiago of the labor market in Chile, which began in 2003 and was carried out by the School of Management and Economics at the Universidad Católica Silva Henríquez. The study includes background on the concepts of employment and unemployment in this group of the population, and the identification of those who, in his opinion, would be responsible for the poor to get a job and the rating assigned to their management. It also includes their perceptions of the support of the state, unemployment, social capital influence, respect for workers, equal opportunities, union power, among other things, besides the level of unemployment and type of family labor problems they have faced.Keywords: labor market, poverty, perceptions, equity.

Social Cohesion, Breaks, and Transformations in Italy, 535–600

2018 ◽  
Author(s):  
Walter Pohl
Keyword(s):  
The Political ◽  
Late Antique ◽  
Religious Context ◽  
Ancient Society ◽  
Complex Process ◽  
Term Change ◽  
Two Generations ◽  
Classical Culture

When the Gothic War began in Italy in 535, the country still conserved many features of classical culture and late antique administration. Much of that was lost in the political upheavals of the following decades. Building on Chris Wickham’s work, this contribution sketches an integrated perspective of these changes, attempting to relate the contingency of events to the logic of long-term change, discussing political options in relation to military and economic means, and asking in what ways the erosion of consensus may be understood in a cultural and religious context. What was the role of military entrepreneurs of more or less barbarian or Roman extraction in the distribution or destruction of resources? How did Christianity contribute to the transformation of ancient society? The old model of barbarian invasions can contribute little to understanding this complex process. It is remarkable that for two generations, all political strategies in Italy ultimately failed.

scholarly journals Effect of captivity on morphology: negligible changes in external morphology mask significant changes in internal morphology

2018 ◽  
Vol 5 (5) ◽  
pp. 172470 ◽  
Author(s):  
Stephanie K. Courtney Jones ◽  
Adam J. Munn ◽  
Phillip G. Byrne
Keyword(s):  
Sexual Dimorphism ◽  
Captive Breeding ◽  
Morphological Changes ◽  
External Morphology ◽  
Wild Animals ◽  
Internal Morphology ◽  
In Captivity ◽  
Two Generations ◽  
Breeding Programmes ◽  
Source Populations

Captive breeding programmes are increasingly relied upon for threatened species management. Changes in morphology can occur in captivity, often with unknown consequences for reintroductions. Few studies have examined the morphological changes that occur in captive animals compared with wild animals. Further, the effect of multiple generations being maintained in captivity, and the potential effects of captivity on sexual dimorphism remain poorly understood. We compared external and internal morphology of captive and wild animals using house mouse ( Mus musculus ) as a model species. In addition, we looked at morphology across two captive generations, and compared morphology between sexes. We found no statistically significant differences in external morphology, but after one generation in captivity there was evidence for a shift in the internal morphology of captive-reared mice; captive-reared mice (two generations bred) had lighter combined kidney and spleen masses compared with wild-caught mice. Sexual dimorphism was maintained in captivity. Our findings demonstrate that captive breeding can alter internal morphology. Given that these morphological changes may impact organismal functioning and viability following release, further investigation is warranted. If the morphological change is shown to be maladaptive, these changes would have significant implications for captive-source populations that are used for reintroduction, including reduced survivorship.

scholarly journals The Effect of Heterogenous Subregions in Glioblastomas on Survival Stratification: A Radiomics Analysis Using the Multimodality MRI

2021 ◽  
Vol 20 ◽  
pp. 153303382110330
Author(s):  
Lulu Yin ◽  
Yan Liu ◽  
Xi Zhang ◽  
Hongbing Lu ◽  
Yang Liu
Keyword(s):  
Poor Prognosis ◽  
Intratumor Heterogeneity ◽  
Short Term ◽  
Prognostic Information ◽  
Manual Delineation ◽  
Flair Sequence ◽  
The Poor ◽  
Contrast Enhanced ◽  
Mri Sequences

Intratumor heterogeneity is partly responsible for the poor prognosis of glioblastoma (GBM) patients. In this study, we aimed to assess the effect of different heterogeneous subregions of GBM on overall survival (OS) stratification. A total of 105 GBM patients were retrospectively enrolled and divided into long-term and short-term OS groups. Four MRI sequences, including contrast-enhanced T1-weighted imaging (T1C), T1, T2, and FLAIR, were collected for each patient. Then, 4 heterogeneous subregions, i.e. the region of entire abnormality (rEA), the regions of contrast-enhanced tumor (rCET), necrosis (rNec) and edema/non-contrast-enhanced tumor (rE/nCET), were manually drawn from the 4 MRI sequences. For each subregion, 50 radiomics features were extracted. The stratification performance of 4 heterogeneous subregions, as well as the performances of 4 MRI sequences, was evaluated both alone and in combination. Our results showed that rEA was superior in stratifying long-and short-term OS. For the 4 MRI sequences used in this study, the FLAIR sequence demonstrated the best performance of survival stratification based on the manual delineation of heterogeneous subregions. Our results suggest that heterogeneous subregions of GBMs contain different prognostic information, which should be considered when investigating survival stratification in patients with GBM.

scholarly journals R Coronae Borealis Stars: Long-Term Photometric & Spectroscopic Studies

1998 ◽  
Vol 11 (1) ◽  
pp. 379-379
Author(s):  
P.L. Cottrell ◽  
L. Skuljan ◽  
P.M. Kilmartin ◽  
C. Gilmore ◽  
W.A. Lawson
Keyword(s):  
Radial Velocity ◽  
Spectroscopic Studies ◽  
Photometric Data ◽  
Decline Phase ◽  
Dust Clouds ◽  
Medium Resolution ◽  
Formation And Evolution ◽  
R Coronae Borealis Stars ◽  
Insight Into

For more than a decade we have been able to acquire and analyse a significant amount of photometric data of the highly variable R Coronae Borealis (RCB) stars. This has made been possible by a photometric service observing programme instigated at the Observatory. These photometric data have been combined with less extensive spectroscopic coverage, particularly of the decline phase of these stars. These have been supplemented by observations obtained at Mount Stromlo and Siding Spring Observatories for a radial velocity study. Significantly more spectroscopic observations are now being acquired with the development of a new medium resolution spectrograph at Mount John University Observatory. In this poster we will present recent photometric and spectroscopic results for a number of the RCB stars in our sample. This observational and analysis work can be used to provide further insight into the nature of these stars, their likely progeny and progenitors and the processes that are involved in the formation and evolution of the obscuring dust clouds which cause the decline phase.

Sign in / Sign up

Export Citation Format

Share Document