Short-term Carry-over Effects Research Articles

Longer days, larger grays: carryover effects of photoperiod and temperature in gray treefrogs, Hyla versicolor.

Environmental conditions like temperature and photoperiod can strongly shape organisms' growth and development. For many ectotherms with complex life cycles, global change will cause their offspring to experience warmer conditions and earlier-season photoperiods, two variables that can induce conflicting responses. We experimentally manipulated photoperiod and temperature during gray treefrog (Hyla versicolor) larval development to examine effects at metamorphosis and during short (10-day) and long (56-day) periods post-metamorphosis. Both early- and late-season photoperiods (April and August) decreased age and size at metamorphosis relative to the average-season (June) photoperiod, while warmer temperatures decreased age but increased size at metamorphosis. Warmer larval temperatures reduced short-term juvenile growth but had no long-term effect. Conversely, photoperiod had no short-term carryover effect, but juveniles from early- and late-season larval photoperiods had lower long-term growth rates than juveniles from the average-season photoperiod. Similar responses to early- and late-season photoperiods may be due to reduced total daylight compared with average-season photoperiods. However, juveniles from late-season photoperiods selected cooler temperatures than early-season juveniles, suggesting that not all effects of photoperiod were due to total light exposure. Our results indicate that despite both temperature and photoperiod affecting metamorphosis, the long-term effects of photoperiod may be much stronger than those of temperature.

Carryover Effects of Pain Neuroscience Education on Patients with Chronic Lower Back Pain: A Systematic Review and Meta-Analysis.

Background and Objectives: Because most individuals with chronic back pain (CLBP) have no specific cause, it is usually described as central sensitization. Pain neuroscience education (PNE) in top-down pain control may be effective against carryover effects; however, this remains unclear. In this study, the carryover effect was qualitatively and quantitatively synthesized and analyzed. Materials and Methods: Randomized controlled trials (RCTs) on PNE in individuals with CLBP were conducted using international databases until January 2023. Using RevMan5.4 provided by Cochrane, qualitative and quantitative analyses were performed with a risk of bias and meta-analysis, respectively. Results: Nine RCTs involving 1038 individuals with CLBP were included in the analysis. Four main results were identified: First, PNE had a short-term carryover effect on pain intensity (SMD = -1.55, 95% confidence interval [CI] = -2.59 to -0.50); second, PNE had a short-term carryover effect on pain catastrophizing (SMD = -2.47, 95% CI = -3.44 to -1.50); third, PNE had short- and long-term carryover effects on kinesiophobia (SMD = -3.51, 95% CI = -4.83 to -2.19); fourth, the appropriate therapeutic intensity of PNE for the pain intensity of individuals (SMD = -0.83, 95% CI = -1.60 to -0.07). Conclusions: PNE has a short-term carryover effect on pain intensity and pain cognition in individuals with CLBP and a long-term carryover effect on kinesiophobia.

Does carnivory pay off? Experiments on the effects of different types of diet on growth and development of Bufo bufo (Linnaeus, 1758) tadpoles and carry-over effects after metamorphosis

Natural diets of anuran larvae vary widely in their relative amounts of nutrients. The proportion of these ingested nutrients has significant influence on larval and post-metamorphic performance. Here, we use the Common Toad to address the role of diet (exclusively carnivore, exclusively vegetarian and mixed) on growth and development of tadpoles and short-term carry-over effects on post-metamorphic animals. Larvae fed on an exclusively vegetarian diet performed better (faster growth and development) than larvae fed on exclusively carnivore and mixed diets. Larvae fed on the exclusively carnivore diet had the lowest performance. Regarding the carry-over effects of larval diets, although the body condition indices of the toadlets were similar in all treatments, there was a major difference in the survival rate. While toadlets, originating from larvae fed on a vegetarian diet, were more successful and had the lowest mortality, those fed on a carnivore diet had the highest mortality level. Our results suggest that a plant-based diet may contain all the necessary nutrients needed by Bufobufo larvae. Furthermore, a diet based exclusively on food of animal origin might be detrimental for the larval performance and could have significant carry-over effects on the post-metamorphic animal.

Effects of an individual weight-adjusted feeding strategy in early lactation on milk production of Holstein cows during extended lactation

Extending lactation by voluntarily delaying rebreeding aims to improve fertility and milk production in the modern dairy cow. Previous studies have shown that increased energy concentrations in the ration induced greater total milk yield and lactation persistency defined by the duration and the shape of the lactation curve. In this paper, we hypothesized that increasing the supply of energy during the early lactation mobilization period would have a positive carryover effect on milk production during extended lactation. A total of 53 Holstein cows completed a 16-mo lactation, including 30% primiparous cows. The cows were divided into 2 feeding strategies: half of the cows received a high-energy density diet (HD) in early lactation followed by a lower-energy density diet (LD; strategy HD-LD). The change in diet was defined individually after 42d of lactation, and when the live weight (LW) gain of the cow was ≥0 based on a 5-d average. The other half of the cows were fed the LD diet during the entire lactation (strategy LD-LD). Both groups received 3kg of concentrates per day during milking. Weekly milk composition (fat, protein, lactose, and somatic cells), daily milk production, daily feed intake, daily LW, and body condition score every second week were recorded. The fda package of R was used to model the curves of these different variables for the 53 cows that had a lactation over 400d. The fitted values of these curves and the associated slopes were then compared for parity and treatment effects using a linear mixed-effects model. The HD-LD and LD-LD cows had a similar length of lactation (461±7 d). The HD diet reduced the intensity of the mobilization period and increased the milk production of the multiparous cows in early lactation compared with the cows fed the LD diet. The primiparous cows used the extra energy to grow and gain weight, but not to produce more milk. After the shift in diet, the treatment had little short-term carryover effect on milk yield or LW, but it affected the slopes of some curves. From 0 to 50d from shift, milk fat content of the LD-LD cows decreased faster than that of the HD-LD cows whereas milk lactose increased. From 250 to 350d from shift, the energy-corrected milk decreased faster for the HD-LD cows than for the LD-LD cows. The lactose content in milk decreased faster for the LD-LD cows than for the HD-LD cows, and the fat content in milk was significantly higher for the primiparous HD-LD than for the primiparous LD-LD cows. In conclusion, the supply of extra energy during the mobilization period had a 300-d negative carryover effect on lactation persistency.

Physiological and Behavioral Responses to an Acute-Phase Response in Zebra Finches: Immediate and Short-Term Effects

Activation of the immune system to clear pathogens and mitigate infection is a costly process that might incur fitness costs. When vertebrates are exposed to pathogens, their first line of defense is the acute-phase response (APR), which consists of a suite of physiological and behavioral changes. The dynamics of the APR are relatively well investigated in mammals and domesticated birds but still rather unexplored in passerine birds. In this study, we injected male zebra finches (Taeniopygia guttata) with a bacterial endotoxin (lipopolysaccharide [LPS]) to assess the potential physiological, immunological, and behavioral responses during the time course of an APR and also to record any potential short-term effects by measuring the birds during the days after the expected APR. We found that LPS-injected zebra finches decreased activity and gained less body mass during the APR, compared to control individuals. In addition, LPS-injected birds increased their production of LPS-reactive antibodies and reduced their metabolic rate during the days after the expected APR. Our results show that zebra finches demonstrate sickness behaviors during an APR but also that physiological effects persist after the expected time course of an APR. These delayed effects might be either a natural part of the progression of an APR, which is probably true for the antibody response, or a short-term carryover effect, which is probably true for the metabolic response.

The Effect of a Single Session of Short Duration Biofeedback-Induced Deep Breathing on Measures of Heart Rate Variability During Laboratory-Induced Cognitive Stress: A Pilot Study

This study examines the acute effect of heart rate variability (HRV) biofeedback on HRV measures during and immediately after biofeedback and during the following laboratory-induced stress. Eighteen healthy males exposed to work-related stress were randomised into an HRV biofeedback group (BIO) or a comparative group (COM). Subjects completed a modified Stroop task before (Stroop 1) and after (Stroop 2) the intervention. Both groups had similar physiological responses to stress in Stroop 1. In Stroop 2, the COM group responded similarly to the way they did to Stroop 1: respiratory frequency (RF) and heart rate (HR) increased, RMSSD and high frequency (HF) power decreased or had a tendency to decrease, while low frequency (LF) power showed no change. The BIO group responded differently in Stroop 2: while RF increased and LF power decreased, HR, RMSSD and HF power showed no change. In the BIO group, RMSSD was higher in Stroop 2 compared to Stroop 1. In conclusion, HRV biofeedback induced a short term carry-over effect during both the following rest period and laboratory-induced stress suggesting maintained HF vagal modulation in the BIO group after the intervention, and maintained LF vagal modulation in the COM group.

The attentional cost of external rhythmical cues and their impact on gait in Parkinson’s disease: effect of cue modality and task complexity

Changes in gait performance in 153 subjects with PD using three rhythmical cues (auditory, visual and somatosensory) were measured during a simple walking task and a dual walking task in the home. Subjects were 'on' medication and were cued at preferred step frequency. Accelerometers recorded gait and walking speed, step amplitude and step frequency were determined from raw data. Data were analysed with SAS using linear regression models. Gait performance during a single task reduced with cues in contrast to a dual task where PD subjects appeared to benefit from rhythmical cues (increased speed and step length). Effects were dependent on cue modality with significant improvements for auditory cues compared to others. A significant short-term carry-over effect of cues reduced 3 weeks later. Cues may reduce attentional demands by facilitating attentional allocation, accounting for differences of cue seen during single and dual task. Furthermore cue modality may influence attentional demand which is an important consideration for rehabilitation.

An analysis of the "carry-over effect" following successful short-term treatment of transformed migraine with divalproex sodium.

To determine whether successful short-term prophylactic treatment of transformed migraine may be followed by a continued respite from headaches once the treatment has been discontinued ("carry-over effect"). The optimal duration of prophylactic treatment for pervasive headache and for migraine, in particular, is unknown. We prospectively evaluated a series of patients with transformed migraine, all of whom were managed according to a uniform treatment protocol involving prophylactic therapy with divalproex sodium for a period not exceeding 12 weeks. All patients reporting a positive treatment response were followed for at least 2 months after the discontinuation of divalproex sodium, and the incidence of the carry-over effect in that group was assessed. A short-term carry-over effect occurred in 12 (60%) of 20 patients, but more sustained relief occurred in only 8 (40%). The successful short-term treatment of transformed migraine with divalproex sodium will often produce a short-term carry-over effect, but this response will be sustained only in a minority of patients.

Relationship between temperature, respiratory loss of sugar and premature dehardening in dormant Scots pine seedlings.

Increased intracellular sugar concentration is an important contributor to the increased cold tolerance of conifers in winter. This study examines the extent to which wintertime respiratory loss of sugars leads to premature dehardening. Two-year-old seedlings of Scots pine (Pinus sylvestris L.), grown and cold-hardened in the field, were exposed to different temperature regimes for 16 weeks while dormant. To minimize short-term carry-over effects, after the temperature treatments, all seedlings were conditioned to 5.5 degrees C and watered before the assessment of non-structural carbohydrates and cold tolerance. Needle sugar concentration was decreased by 54, 32, 21 and 9% following treatment at 5.5, 0, -1.5 and -8.5 degrees C, respectively. Sugar concentration did not decrease as much in root tissues as in needles because starch was mobilized in roots. Cold tolerance of needles was analyzed by controlled freezing, and the temperature causing an initial 10% damage (LT(10)) was plotted as a function of needle sugar concentration, revealing a strong, linear relationship. When one-third of the initial sugars had been consumed, LT(10) had increased from -24.5 to -16.5 degrees C, and when one half had been consumed, LT(10) had increased to -10 degrees C. Consequences of these findings for the field performance of conifers are discussed in relation to climatic variation and change.

Discrimination and Patch Choice by Sheep Grazing Grass-Clover Swards

1. The proposition that large herbivores make foraging choices which maximize intake rate was examined in two experiments on discrimination by sheep grazing pairs of swards (patches) varying in composition of two botanical components, grass and clover, and varying in sward surface height. 2. Patch selection was influenced by sward height and by clover content, and their effects were additive. Tall patches were preferred, and intermediate contents of clover were selected in preference to low or high contents. This would reinforce the patchy distribution of the grass and clover components of mixed swards. Sheep did not exploit local variation in clover content within patches. 3. There was no evidence that patch choice was influenced by differences in the intake rate obtained from the two alternatives at hand, although on average the highest intake rates were obtained on tall patches with intermediate clover contents, coincident with the pattern of preference. 4. During frequent switching between patches, components of the functional response such as bite depth, bite weight and intake rate were modified by patch composition and also by the composition of the alternate patch. This short-term carry-over effect must increase the discrimination difficulties on heterogeneous vegetation. 5. It is argued that pre-consumption cues signalling patch quality are of less use to sheep than the information gained about a patch during grazing, but that this is initially distorted by recent experience; and that information constraints on the maximization of long-term intake rate will occur during frequent switching within heterogeneous vegetation.