Winter torpor in Helix pomatia: regulated defence mechanism or forced inactivity?

2005 ◽  
Vol 83 (12) ◽  
pp. 1608-1613 ◽  
Author(s):  
M Caputa ◽  
A Nowakowska ◽  
J Rogalska ◽  
K Wentowska
Keyword(s):  
Helix Pomatia ◽  
Thermal Conditions ◽  
Early Spring ◽  
Cold Weather ◽  
Threshold Temperature ◽  
Defence Mechanism ◽  
Natural Habitats ◽  
Natural Photoperiod ◽  
Thermal Preferences ◽  
Spring Snails

We examined Helix pomatia L., 1758 snails to answer two questions. First, is their winter dormancy facilitated by cold-seeking behaviour, or is it rather a passive phenomenon imposed by cold weather? Second, what thermal conditions are necessary to arouse these snails out of torpor in midwinter and in spring? Snails, collected from natural habitats, were placed in a temperature-gradient apparatus. Their thermal preference was recorded for 48 h under natural photoperiod in early spring, midsummer, and autumn. The autumn recording was continued until the end of November on non-starved and starved snails. Two additional sessions were performed on torpid snails in January (latencies of arousals from torpor at various temperatures and immediate thermal preferences were recorded) and in February (they were kept permanently in darkness at 5 °C and their spontaneous arousals were examined). Temperature selected in spring (23.60 ± 0.15 °C) was significantly lower than that in summer (26.90 ± 0.05; P < 0.05) and in autumn (27.50 ± 0.10 °C; P < 0.01). The prolonged autumn recording did not show cold-seeking behaviour either in non-starved or in starved snails. Threshold temperature inducing midwinter arousals was 10 °C and the aroused snails immediately selected temperatures indistinguishable from those in summer and autumn. Spontaneous arousals from torpor in the snails continuously exposed to cold occurred within a period of arousals in the field. In conclusion, winter torpor of the snails displays unique properties, i.e., its start and maintenance are passive phenomena, while its spring interruption is a precisely controlled, endogenous mechanism.

The productivity of breeding ewes grazing on lucerne or grass and clover pastures on the tablelands of Southern Australia. III. Lamb mortality and weaning percentage

1984 ◽  
Vol 35 (5) ◽  
pp. 709 ◽  
Author(s):  
JR Donnelly
Keyword(s):  
Early Spring ◽  
Practical Significance ◽  
Cold Weather ◽  
Late Winter ◽  
Maternal Weight ◽  
Risk Of Death ◽  
Probability Of Death ◽  
The Difference ◽  
Stocking Rates

Weaning percentage and perinatal mortality of lambs born in late winter or early spring to Merino and Border Leicester x Merino ewes grazing at several stocking rates on lucerne or phalaris-clover pastures were measured over 2 years. Weaning percentages for mature crossbred ewes declined linearly from 136 lambs per 100 ewes joined when stocked at 9 ha-1 to 100 for those at 18 ha-1. For mature Merino ewes, the values were 109 and 70 respectively. Weaning percentages were similar on lucerne and phalaris pastures, although 8% more lambs were born to ewes grazing on phalaris; higher mortality in lambs born as multiples eliminated the difference. Death from exposure during the first 3 days of life was the most important cause of lamb losses. For lambs born as singles to Merino ewes the probability of death from exposure was up to 0.4, and reached 0.6 for lambs born as multiples. For single and multiple lambs born to crossbred ewes equivalent probabilities were 0.25 and 0.4 respectively. These probabilities were reduced if maternal weight was high at lambing, the reduction being of practical significance in very cold weather, particularly if the proportion of multiple births was high. Under mild conditions, where the probability of death from exposure was low, reductions in mortality from high ewe weight at lambing were of little consequence. Long-term weather records kept at the experimental site near Canberra show that a high risk of death in new-born lambs is likely from early June to mid-September. Throughout this period deaths from exposure could be expected to exceed 30% in lambs born as multiples to Merino ewes.

Efficiency of night interruption treatments with red and far-red light-emitting diodes (LEDs) in preventing bud set in Norway spruce seedlings

2018 ◽  
Vol 48 (9) ◽  
pp. 1001-1006 ◽  
Author(s):  
Johanna Riikonen
Keyword(s):  
Norway Spruce ◽  
Light Emitting Diodes ◽  
Red Light ◽  
Growth Conditions ◽  
Early Spring ◽  
Light Emitting ◽  
Bud Set ◽  
Terminal Bud ◽  
Natural Photoperiod ◽  
Terminal Buds

Terminal bud set can be prevented by interrupting night with short pulses of light when the natural photoperiod is too short to maintain growth. Norway spruce (Picea abies Karst.) seedlings originating from 61°N and 64°N were grown in growth chambers under conditions that mimic growth conditions in a heated greenhouse in early spring in Finland (experiment 1) or under constant growth conditions (experiment 2). The seedlings were exposed to the following night interruption (NI) treatments using light-emitting diodes (LEDs) that generated red (R, peak at 660 nm) and far-red (FR, peak at 735 nm) wavelengths in 20 s pulses at 15 min intervals: (i) red light alone (R); (ii) R combined with FR (R + FR); and (iii) control (no NI treatment). The R + FR treatment was more effective in preventing terminal bud set than the R treatment. Seedling responses depended on the provenance and growth conditions. The R treatment reduced the proportion of seedlings with terminal buds in the 61°N seedlings and delayed bud set in the 64°N seedlings. The fluctuating growth conditions or longer dark period between the photoperiod and NI treatments reduced the efficiency of the R + FR treatment. A combination of R and FR LEDs with adequate light intensity and duration is suitable for intermittent NI treatment in Norway spruce seedlings.

Effect of winter torpor upon antioxidative defence in Helix pomatia

2009 ◽  
Vol 87 (6) ◽  
pp. 471-479 ◽  
Author(s):  
Anna Nowakowska ◽  
Grażyna Świderska-Kołacz ◽  
Justyna Rogalska ◽  
Michał Caputa
Keyword(s):  
Oxidative Damage ◽  
Reduced Glutathione ◽  
Helix Pomatia ◽  
Redox Balance ◽  
Middle Part ◽  
Land Snails ◽  
Natural Habitats ◽  
Antioxidative Defence ◽  
Antioxidant Defence System ◽  
Snail Helix Pomatia

Arousal of land snails from torpor is inseparably connected with an increase in oxygen consumption leading to oxidative stress. Therefore, activity of antioxidant defence system (antioxidant enzymes and reduced glutathione) and degree of oxidative damage (concentration of malondialdehyde as an index of lipid peroxidation) in the snail Helix pomatia L., 1758 were tested to check whether torpid snails are able to activate their antioxidative defence against oxidative damage prior to arousal from winter torpor. Snails, which were collected from their natural habitats, were tested at the beginning, in the middle part, and at the end of winter torpor. Active snails collected in autumn and spring were taken as control groups. Snails were immediately killed and their foot, hepatopancreas, and kidney were used for the biochemical assays. Winter torpor induced significant changes in activities of the crucial antioxidant substances. The lowest activities were observed at the beginning of torpor, whereas activity of some of these enzymes was significantly enhanced prior to spring arousal. Reduced glutathione concentration did not show time-dependent changes during winter torpor. MDA (1,3-propanedial) level was elevated in the kidney and foot but was unchanged in the hepatopancreas. In conclusion, the snail H. pomatia is able to maintain REDOX balance necessary to prevent oxidative injury during arousal.

scholarly journals ANALISIS PENGARUH BENTUK SERAMBI MASJID TERHADAP KENYAMANAN TERMAL ADAPTIF

2020 ◽  
Vol 4 (3) ◽  
pp. 261
Author(s):  
Abdul Qodir ◽  
Erni Setyowati ◽  
Suryono Suryono
Keyword(s):  
Thermal Comfort ◽  
Thermal Environment ◽  
Thermal Conditions ◽  
Temperature Range ◽  
Adaptive Thermal Comfort ◽  
Environment Variables ◽  
Average Condition ◽  
Radiant Temperature ◽  
Thermal Preferences ◽  
Neutral Conditions

This study examines the effect of the porch on the adaptive thermal comfort of mosques by taking 2 mosques that have different porch shapes with the specific purpose of obtaining data on the neutrality, acceptability and preferences of the mosque respondents' thermal conditions in the framework of developing adaptive thermal comfort standards for Indonesia. Measurement of physical environment variables is done by taking data on temperature, humidity, air velocity, and mean radiant temperature (MRT) at 2 mosques and at the same time the impression and thermal preference questionnaire data are taken, examination of clothing types and activities, and list of thermal environment controls to 40 respondents in each mosque. Data of thermal neutrality and thermal preferences were analyzed by regression analysis using SPSS 19 software, while thermal acceptance was analyzed based on the results of the questionnaire answers. The analysis showed that the neutrality value at Ulul Albab mosque was Tdb = 28.47 OC, ET * = 30.11 OC, SET * = 23.11 OC, TSENS = 1.17, DISC = -1.06, and PMV = -0.65, this data shows that the neutral condition desired by respondents is slightly below the average condition, while the neutrality in Nurul Ilmi mosque at Tdb = 30.27 OC, ET * = 31.65 OC, SET * = 29.05 OC, TSENS = 1.03, DISC = 1.68, and PMV = 1.22, this data also shows that the neutral conditions desired by respondents are slightly below average conditions. While the preference value at Ulul Albab mosque is Tdb = 22.25 OC, ET * = 28.62 OC, SET * = 24.24 OC, TSENS = 0.23, DISC = 0.23, and PMV = -0.60 and preference conditions at Nurul Ilmi mosque at Tdb = 29.11 OC, ET * = 31.17 OC, SET * = 28.50 OC, TSENS = 1.04, DISC = 1.45, and PMV = 1.03. As many as 92% of respondents in the Ulul Albab mosque can accept local thermal conditions in the temperature range of 27oC - 31oC. While 90% of respondents in the Nurul Ilmi mosque can accept local thermal conditions in the temperature range of 27oC-32oC. The results of the neutrality, acceptance and preference analysis show that the Ulul Albab mosque is better than the Nurul Ilmi mosque.

scholarly journals Bioclimatic conditions and thermal seasons of the year in Szczecin

2021 ◽  
Vol 94 (2) ◽  
pp. 283-299
Author(s):  
Agnieszka Mąkosza
Keyword(s):  
Climate Change ◽  
Air Temperature ◽  
Meteorological Data ◽  
Thermal Conditions ◽  
Thermal Spring ◽  
Early Spring ◽  
Climate Index ◽  
Relative Air Humidity ◽  
Thermal Climate ◽  
Bioclimatic Conditions

Climate change is an empirical fact evidenced by subsequent IPCC reports. The observed climate change is also manifested in the altered date of occurrence and duration of the seasons in a year. Variability of thermal conditions due to climate warming will have its toll on the bioclimatic conditions. The assessment of bioclimatic conditions was conducted with the use of Universal Thermal Climate Index (UTCI). The present elaboration is based on hourly values of the following meteorological elements: air temperature, relative air humidity, wind speed and cloud cover. The meteorological data were obtained from the Institute of Meteorology and Water Management – National Research Institute (IMGW-PIB) in Szczecin and cover the period 2000-2019. Variability of bioclimatic conditions is considered per periods corresponding to thermal seasons of the year as identified by the Gumiński (1948) method on the basis of monthly air temperature values. The analysed UTCI values with respect to thermal seasons indicate that mean UTCI values in the period 2000-2019 representative for thermal summer amount to 22.6°C, thermal spring 9,9°C, thermal autumn 8.4°C, thermal winter -10.4°C, early spring -4.6°C, and early winter -7.9°C. For the periods with identified lack of thermal winter, mean UTCI value was -6.6°C. The aim of the present paper is an attempt to assess the variability of biothermal conditions as calculated using the UTCI index against the thermal seasons of the year in Szczecin.

scholarly journals Changes inSenna obstuifoliaGermination Requirements over 12 Months under Field Conditions

2009 ◽  
Vol 2009 ◽  
pp. 1-5
Author(s):  
Jason K. Norsworthy ◽  
Marcos J. Oliveira
Keyword(s):  
Thermal Conditions ◽  
Early Spring ◽  
Field Conditions ◽  
Specific Time ◽  
Physical Dormancy ◽  
Light Requirement ◽  
Thermal Requirements ◽  
Senna Obtusifolia ◽  
Temperature Requirements

Senna obtusifoliaseeds were collected in Fall 2003 and immediately field sown to assess dormancy alleviation and effect of after-ripening over a 12-month period on light and temperature requirements for germination. Seeds did not exhibit physical dormancy at maturation and readily germinated over a broad range of light and thermal conditions. Dormancy gradually increased during Winter months, resulting in only a small fraction of the population capable of germination by early Spring. Dormancy break did not occur at a specific time of the year nor did dormancy alleviation increase over the 12-month period following maturation. Conditions during Spring and Summer coincided with thermal requirements for germination of the nondormant fraction of the population.Senna obtusifoliaseeds were nonresponsive to red and far-red lights, and seeds did not acquire a light requirement following burial for 6 months.

scholarly journals Variability in stream discharge and temperatures during ecologically sensitive time periods: a preliminary assessment of the implications for Atlantic salmon

2005 ◽  
Vol 2 (3) ◽  
pp. 691-729 ◽  
Author(s):  
D. Tetzlaff ◽  
C. Soulsby ◽  
A. F. Youngson ◽  
C. Gibbins ◽  
P. J. Bacon ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Juvenile Fish ◽  
Management Strategies ◽  
Thermal Conditions ◽  
Early Spring ◽  
Regulated River ◽  
High Temporal Resolution ◽  
Hydrological Variability ◽  
Discharge Temperature ◽  
Time Periods

Abstract. This study focused on improving the understanding of the temporal variability in hydrological and thermal conditions and their potential influences on two life stages of Atlantic salmon (Salmo salar) – stream resident juveniles and returning adult spawners. Stream discharges and temperatures in the Girnock Burn, NE Scotland, a small nursery stream, were characterised over a time period of ten hydrological years (1994/95–2003/04). Frequency, magnitude, duration and timing of thermal, hydraulic and hydrological conditions were examined using data with a high temporal resolution (hourly and subhourly). Particular attention was focussed on assessing variations during ecologically sensitive time periods when salmon behaviour is most susceptible to environmental perturbations. The Girnock Burn was characterised by a strong inter- and intra-annual variability in the hydrological and thermal regime. This has clear implications for the likely feeding opportunities for juvenile fish in winter and early spring and the emergence of fry in the late spring. The movement of adult spawners towards breeding areas showed a complex dependence on hydrological variability. If discharges were low, fish movement was increasingly triggered by suboptimal flow increases as spawning time approached. Elucidating links between discharge/temperature variability and salmon habitat availability and utilization at appropriately fine temporal scales is a prerequisite to the development of better conservation management strategies and more biologically meaningful flow regimes in regulated river systems.

scholarly journals Thermo Condition Determines the Uptake of Autumn and Winter Applied Nitrogen and Subsequent Utilization in Spring Tea (Camellia sinensis L.)

Horticulturae ◽  
2021 ◽  
Vol 7 (12) ◽  
pp. 544
Author(s):  
Lifeng Ma ◽  
Shuangfeng Jiang ◽  
Min Deng ◽  
Lize Lv ◽  
Ze Xu ◽  
...  
Keyword(s):  
Camellia Sinensis ◽  
Thermal Condition ◽  
Thermal Conditions ◽  
Early Spring ◽  
N Fertilizer ◽  
Degree Days ◽  
Fibrous Root ◽  
Mature Leaves ◽  
Timing Effect ◽  
Autumn And Winter

The effect of thermal condition on the uptake of autumn and winter applied N and its subsequent utilization in spring tea (Camellia sinensis) was investigated by applying 15N enriched urea as single or split applications between October and February in two commercial plantations at Xingyang of Henan province and Yongchuan of Chongqing with different thermal conditions. The proportion of N derived from 15N-labeled urea (Ndff%) in fibrous root and mature leaves 15 days after application at Xingyang and the Ndff% of mature leaves on the day of the first spring tea harvest at both sites were the highest in the single October application. The Ndff% of the following spring tea was also the highest in the single October application at both sites. The results showed that application of N fertilizer in October relative to other later months most significantly improves the accumulation of plant N reserves and consequently contributes more significantly to the early spring tea. Such timing effect was related to the thermal condition, i.e., the growing degree days (°C•d, T > 8 °C) between the dates of fertilization and harvest of young shoots, which represents the combining effect of the temperature and the residence time of N fertilizer in the soil.

scholarly journals Efficiency of forest planting in the spring and autumn periods in the conditions of the Republic of Kalmykia

2021 ◽  
Vol 843 (1) ◽  
pp. 012057
Author(s):  
M V Kostin
Keyword(s):  
Survival Rate ◽  
Forest Cover ◽  
Early Spring ◽  
Cold Weather ◽  
Correct Selection ◽  
Young Forest ◽  
Dry Steppe ◽  
European Part Of Russia ◽  
Zonal Section ◽  
The Republic

Abstract The Republic of Kalmykia is the driest region in the south of the European part of Russia. The purpose of the study is to find a new approach to reforestation and breeding in the republic, which will ensure the increase in the survival rate of forest crops, and subsequently increase the forest cover of the region. The article analyzes data for a ten-year period in a zonal section on the survival rate of tree and shrub species cultivated in the forestry of the Republic of Kalmykia. It is concluded that carrying out forest cultivation works in the autumn period has no advantages in survival rate over the spring period and they should be carried out either in early spring (in late March and early April) on thawing soil, or in autumn, before the onset of persistent cold weather. The main factor of successful afforestation in the dry steppe and semi-desert is the correct selection of the forest area, the accuracy and quality of forest planting, agrotechnical and forestry care. Special attention should be paid to the control of locust pests, which in the conditions of Kalmykia in some years can cause significant damage to the planting of young forest crops.

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