The Role of Energy Availability in Mammalian Hibernation: An Experimental Test in Free‐Ranging Eastern Chipmunks

2003 ◽  
Vol 76 (2) ◽  
pp. 180-186 ◽  
Author(s):  
Murray M. Humphries ◽  
Donald L. Kramer ◽  
Donald W. Thomas
Keyword(s):  
Experimental Test ◽  
Energy Availability ◽  
Eastern Chipmunks ◽  
Free Ranging ◽  
Mammalian Hibernation

The Role of Energy Availability in Mammalian Hibernation: A Cost‐Benefit Approach

2003 ◽  
Vol 76 (2) ◽  
pp. 165-179 ◽  
Author(s):  
Murray M. Humphries ◽  
Donald W. Thomas ◽  
Donald L. Kramer
Keyword(s):  
Cost Benefit ◽  
Energy Availability ◽  
Mammalian Hibernation

scholarly journals An experimental test of the effects of online and face-to-face feedback on self-esteem

2017 ◽  
Vol 11 (4) ◽  
Author(s):  
Helen G. M. Vossen ◽  
Maria Koutamanis ◽  
Joseph B. Walther
Keyword(s):  
Negative Feedback ◽  
Experimental Test ◽  
Indirect Effect ◽  
Online Communication ◽  
Self Esteem ◽  
Communication Mode ◽  
Self Disclosure ◽  
Face To Face ◽  
Negative Comments

This study investigated the effect of receiving confirming vs. disconfirming feedback to individuals’ self-disclosure on their self-esteem, the role of giving reciprocal feedback in this relationship, and how these effects differ between online and face-to-face communication. Using a two (communication mode: online vs. face-to-face) by two (feedback valence: confirming vs. disconfirming) between-subjects experiment, we found that feedback had a significant indirect effect on self-esteem, through the receiver’s reciprocal feedback. This indirect effect of feedback differed in online communication from offline: In online communication, participants reciprocated negative feedback when they received it, more than in face-to-face communication. The reciprocal feedback enhanced their self-esteem in online communication, but not in face-to-face communication. Although people tend to respond more negatively to negative comments in online conversations, the process, overall, boosts rather than hinders their self-esteem.

scholarly journals Increasing photoperiod stimulates the initiation of spring migratory behaviour and physiology in a facultative migrant, the pine siskin

2018 ◽  
Vol 5 (8) ◽  
pp. 180876 ◽  
Author(s):  
Ashley R. Robart ◽  
Mali M. K. McGuire ◽  
Heather E. Watts
Keyword(s):  
Experimental Test ◽  
Spring Migration ◽  
Fat Deposition ◽  
Day Length ◽  
Environmental Cues ◽  
Migratory Restlessness ◽  
Migratory Behaviour ◽  
Behavioural Changes ◽  
Short Day

The transition to a migratory state involves coordinated changes in physiology and behaviour. In species with regular, predictable (obligate) migrations, increasing day length triggers the expression of a spring migratory state and androgens play an important role in stimulating its development. By contrast, we know little about the environmental cues and endocrine mechanisms that regulate migration in species with less predictable (facultative) migrations. Here, we tested whether photoperiod stimulates a migratory state in a facultative nomadic migrant, the pine siskin ( Spinus pinus ). We exposed wintering birds to either a naturally increasing or short-day photoperiod and measured physiological and behavioural changes indicative of a migratory state. We also examined changes in circulating hormones that may play a role in the migratory transition. Natural-day, but not short-day, birds displayed physiological preparations for migration, including increases in fat deposition, and showed increased levels of migratory restlessness. We found no evidence for a role of corticosterone in the migratory transition, but testosterone may be important. This study is the first experimental test of the role of photoperiod in regulating facultative migration and demonstrates that the predictive cue used by many obligate migrants to time spring migration is also important in a facultative migrant.

An Experimental Test of the Role of Alcohol in Relationship Conflict

2000 ◽  
Vol 36 (2) ◽  
pp. 182-193 ◽  
Author(s):  
Geoff MacDonald ◽  
Mark P Zanna ◽  
John G Holmes
Keyword(s):  
Experimental Test ◽  
Relationship Conflict

scholarly journals Fatal pulmonary parafilaroidiasis in a free-ranging subantarctic fur seal (Arctocephalus tropicalis) coinfected with two gammaherpesviruses and Sarcocystis sp.

2019 ◽  
Vol 28 (3) ◽  
pp. 499-503 ◽  
Author(s):  
Laura Reisfeld ◽  
Carlos Sacristán ◽  
Angélica María Sánchez-Sarmiento ◽  
Samira Costa-Silva ◽  
Josué Díaz-Delgado ◽  
...  
Keyword(s):  
Novel Species ◽  
Tissue Response ◽  
Mesenteric Lymph Nodes ◽  
Pathogenic Role ◽  
Mesenteric Lymph ◽  
Verminous Pneumonia ◽  
Fur Seal ◽  
Free Ranging ◽  
Arctocephalus Tropicalis

Abstract A juvenile subantarctic fur seal (Arctocephalus tropicalis) found dead in Santa Catarina state, southern Brazil, presented with disseminated verminous pneumonia due to Parafilaroides sp. A concomitant infection with two different gammaherpesviruses was identified by PCR in different tissues; one of them possibly a novel species (tentatively named Otariid herpesvirus 7). Sarcocystis sp. DNA was identified molecularly in skeletal muscle samples with intrasarcoplasmic bradyzoites and no apparent tissue response. All analyzed samples (mandibular, laryngeal, tracheal, and mesenteric lymph nodes, and lung) were PCR-negative for Brucella spp. The most likely cause of death was severe pulmonary parafilaroidiasis. The pathogenic role of the gammaherpesviruses in several of the tissues was not evident. This study describes the pathogenicity of Parafilaroides sp. in a subantarctic fur seal, widens the host range of herpesvirus in pinnipeds, and reports the first molecular identification of Sarcocystis sp. in this species.

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