Seasonal changes of thermal conductance in Zonotrichia capensis (Emberizidae), from central Chile: the role of plumage

AbstractObservations were made during 1967 to 1969 at Ithaca, N.Y., supplemented by collections at New Cumberland and Carlisle, Pa., on arthropods associated with fungi occurring on alfalfa, Medicago saliva L. Five species of Coleoptera, two species of Diptera, one species each of Collembola and Psocoptera, and nine species of Acari were reared or collected consistently from fungus-covered alfalfa leaves, stems, and seed pods. Attraction to fungi on the plants, principally Alternaria sp., accounted for the presence on alfalfa of arthropod species that normally might be considered as accidentals or visitors. The mycetophagous species thus contributed to the richness of the alfalfa fauna. Immature stages of several species were collected only in late fall or on 3- or 4-year-old plants. The possible role of the fungus-feeding species in seasonal changes in the alfalfa fauna and changes in the fauna in successive years is discussed.

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Role of hydrogen bonds in thermal conductance at the graphene oxide-H2O interface

International Journal of Heat and Mass Transfer ◽

10.1016/j.ijheatmasstransfer.2021.122125 ◽

2022 ◽

Vol 183 ◽

pp. 122125

Author(s):

Shanchen Li ◽

Yang Chen ◽

Zhihui Li ◽

Junhua Zhao ◽

Ning Wei

Keyword(s):

Graphene Oxide ◽

Hydrogen Bonds ◽

Thermal Conductance

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Thermoregulation, growth, and reproduction in Alaskan collared lemmings: role of short day and cold

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1991.261.3.r522 ◽

1991 ◽

Vol 261 (3) ◽

pp. R522-R530 ◽

Cited By ~ 1

Author(s):

H. A. Maier ◽

D. D. Feist

Keyword(s):

Food Intake ◽

Thermal Conductance ◽

Reproductive Condition ◽

Reproductive Morphology ◽

Short Day ◽

Long Day ◽

Dicrostonyx Groenlandicus ◽

Before And After ◽

Growth And Reproduction

To assess factors controlling seasonal thermoregulatory and reproductive changes, collared lemmings (Dicrostonyx groenlandicus) were exposed for 16 wk to long day (LD, 22 h light: 2 h dark) and warm (15 +/- 3 degrees C), LD and cold (1 +/- 0.5 degrees C), short day (SD, 4 h light: 20 h dark) and warm, SD and cold or acclimatized to outdoor winter conditions (OUT). Hair length and color, body mass, and food intake were monitored weekly. Resting metabolic rates (RMR) and nonshivering thermogenesis (NST) were estimated several times by measuring oxygen consumption before and after norepinephrine injections. Body composition and reproductive condition were determined at the end of the experiment. SD and OUT groups had a 15.8% lower (P less than 0.01) RMR at 7 degrees C than the LD groups. Lower thermal conductance in SD and OUT animals appears due to molt to white winter pelage, which occurred by week 3 in SD but not in LD groups. Neither SD, cold, nor OUT altered NST or reproductive morphology. SD-exposed lemmings showed 19.2% greater growth than those in LD, resulting primarily from a 29.2 and 15.0% increase in lean and ash components, respectively. Cold exposure increased food intake by 34.7%. Results suggest that the pineal gland, which mediates SD effects, may influence molt and growth but not NST or reproductive morphology.

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Characterizing the Water Storage Capacity and Hydrological Role of Mountain Peatlands in the Arid Andes of North-Central Chile

Water ◽

10.3390/w12041071 ◽

2020 ◽

Vol 12 (4) ◽

pp. 1071 ◽

Cited By ~ 1

Author(s):

Remi Valois ◽

Nicole Schaffer ◽

Ronny Figueroa ◽

Antonio Maldonado ◽

Eduardo Yáñez ◽

...

Keyword(s):

High Altitude ◽

Storage Capacity ◽

Water Storage ◽

Catchment Scale ◽

North Central ◽

Central Chile ◽

Water Storage Capacity ◽

Order Of Magnitude ◽

Local Water

High-altitude peatlands in the Andes, i.e., bofedales, play an essential role in alpine ecosystems, regulating the local water balance and supporting biodiversity. This is particularly true in semiarid Chile, where bofedales develop near the altitudinal and hydrological limits of plant life. The subterranean geometry and stratigraphy of one peatland was characterized in north-central Chile using Electrical Resistivity Tomography (ERT), Ground Penetrating Radar (GPR) and core extraction. Two sounding locations, two transversal and one longitudinal profile allowed a 3D interpretation of the bofedal’s internal structure. A conceptual model of the current bofedal system is proposed. Geophysical results combined with porosity measurements were used to estimate the bofedal water storage capacity. Using hydrological data at the watershed scale, implications regarding the hydrological role of bofedales in the semiarid Andes were then briefly assessed. At the catchment scale, bofedal water storage capacity, evapotranspiration losses and annual streamflow are on the same order of magnitude. High-altitude peatlands are therefore storing a significant amount of water and their impact on basin hydrology should be investigated further.

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Temperature modulation of photoperiodism and the timing of late-season changes in life history for an aphid, Acyrthosiphon pisum

The Canadian Entomologist ◽

10.4039/n10-044 ◽

2011 ◽

Vol 143 (1) ◽

pp. 56-71 ◽

Cited By ~ 1

Author(s):

M.A.H. Smith ◽

P.A. MacKay ◽

R.J. Lamb

Keyword(s):

Sexual Reproduction ◽

Seasonal Changes ◽

Acyrthosiphon Pisum ◽

Late Summer ◽

Day Length ◽

Temperature Modulation ◽

Four Seasons ◽

Aphid Clone ◽

Photoperiodic Responses

AbstractWhere winters are severe, aphids reproduce parthenogenetically and viviparously in summer, switch to sexual reproduction in late summer, and produce winter-hardy eggs by the end of the season. The role of day length and temperature in initiating seasonal changes from parthenogenetic to sexual reproduction by pea aphids, Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae), are described and the selection pressures that affect the timing of this transition are investigated. Over four seasons, a pea aphid clone was sampled from field cages through late summer in southern Manitoba, Canada, and reared in the laboratory to determine the phenotypes of progeny produced as the season progressed. The timing of transitions from one phenotype to another under natural day length and temperature, and the critical day lengths that caused the transitions, coincided with expectations from laboratory studies of photoperiodic responses. Males and mating females appeared later when the weather in August was warm than when it was cool. The timing of seasonal changes was adapted to minimize the physiological time to the end of the season, which maximized the number of asexual summer generations. Ambient temperature modulated the response to day length and fine-tuned the timing of sexual reproduction to adapt for annual variation in autumn weather.

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Study on the Influence of Seasonal Diversity Deduction of Landscape Plants on Landscape Vision

E3S Web of Conferences ◽

10.1051/e3sconf/201913604104 ◽

2019 ◽

Vol 136 ◽

pp. 04104

Author(s):

Shengju Li ◽

Xue Wang ◽

Yaosheng Zhang ◽

Yuehua Zhang ◽

Li Lan

Keyword(s):

Seasonal Changes ◽

Cold Regions ◽

Distinctive Features ◽

Landscape Plant ◽

Planning And Design ◽

Different Seasons ◽

Garden Plants ◽

Seasonal Diversity ◽

Plant Configuration

Urban garden landscape is a topic of great concern in the process of modern urban construction. It belongs to the landscape with vitality in the construction process. The plant landscape is also the product of the combination of economy, politics, culture and technology. The cold land plants belong to the only life-changing and cyclical elements in the garden design process. They use the seasonal changes of their distinctive features to realize the planning and design, which can effectively enrich the overall landscape effect. The seasonal changes of garden plants in cold regions mainly include space and color. The seasonal changes of color include leaves, flowers, fruits and branches, and the spatial characteristics are different periods of plants. In the process of realizing the garden configuration, it is important to comprehensively study the seasonal changes of plants, which can effectively improve the role of gardens. The study analyzes the influence of seasonal changes of garden plants on the landscape construction of garden space from three aspects: function, season and beauty. Therefore, the characteristics of seasonal changes of garden plants in cold regions are analyzed, so as to improve the rationality of landscape plant configuration in different seasons, and improve the level of garden landscape construction.

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The Role of Foreign Workers in the Seasonal Fluctuations of the French Economy

International Migration Review ◽

10.1177/019791838602000407 ◽

1986 ◽

Vol 20 (4) ◽

pp. 856-874

Author(s):

Raphaël-Emmanuel Verhaeren

Keyword(s):

Present Article ◽

Seasonal Changes ◽

Immigrant Workers ◽

Foreign Workers ◽

Seasonal Fluctuations ◽

Seasonal Workers ◽

French Economy

The few studies which have been carried out on foreign seasonal workers in France, only take into account the annual inflows of seasonal immigrants. This present article covers two other aspects of the problem: the seasonal nature of immigration in general, and above all the role of permanent immigrant workers in certain sectors influenced by seasonal changes.

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