Storage In Summer Research Articles

Phenotypic flexibility in passerine birds: Seasonal variation in fuel storage, mobilization and transport

Winter acclimatization in small birds living in cold climates produces a winter phenotype characterized by upregulation of metabolic rates to meet enhanced thermoregulatory demands. We measured several key aspects of fuel storage, mobilization and transport in summer and winter to determine whether black-capped chickadees (Poecile atricapillus), white-breasted nuthatches (Sitta carolinensis), and house sparrows (Passer domesticus) seasonally modulate these attributes to meet enhanced winter thermoregulatory demands. In addition, we exposed birds to thermoneutral (control) and severe cold exposure treatments to determine whether acute cold exposure influenced fuel storage, mobilization or transport. Carcass lipid mass and pectoralis intramuscular lipid did not vary significantly between seasons or temperature treatments for any of the study species. Muscle glycogen varied significantly seasonally only for chickadee supracoracoideus and leg muscles, and did not vary among warm or cold treatments for any species. Pectoralis fatty acid binding protein (FABPc) was significantly elevated in winter for chickadees and nuthatches, but not for sparrows. Plasma metabolites showed little consistent variation in response to season or acute cold exposure. Thus, fuel storage and mobilization do not appear to be major targets of adjustment associated with seasonal metabolic flexibility in these species, but modulation of intracellular lipid transport by FABPc may be an important contributor to seasonal phenotypes in some species of small birds.

Evaluation of a three-phase sorption cycle for thermal energy storage

In recent years, sorption processes are increasingly gaining attention in the field of TES (thermal energy storage), owing to their advantages of high storage density and no significant heat loss during storage process. In this paper, a novel three-phase sorption cycle is proposed and evaluated for TES, to provide cold storage in summer and heat storage in winter. The uniqueness of the cycle is that it allows the solution to reach its crystallized state or even dehydrated state during the charging stage. Three working pairs, namely LiCl/H2O, CaCl2/H2O and LiBr/H2O, are considered for the proposed cycle based on their pressure–temperature-phase diagrams. Detailed analysis reveals that presence of the three-phase crystallization process could extensively improve the energy storage performance, as heat storage densities increase by 43%, 79% and 38% for LiCl/H2O, CaCl2/H2O and LiBr/H2O respectively. Overall, LiCl/H2O is determined to be the best choice among the three couples, with a cold storage density of 519 kWh/m3 (1242 Wh/kg, charged at 90 °C in summer) and a heat storage density of 618 kWh/m3 (1250 Wh/kg, charged at 75 °C in winter). This theoretical evaluation suggests that the three-phase sorption cycle can be a promising solution for TES.

Conceptual model of energy allocation in walleye pollock (Theragra chalcogramma) from age-0 to age-1 in the southeastern Bering Sea

Walleye pollock (Theragra chalcogramma) support the largest commercial fishery in the United States and are an ecologically important component of the southeastern Bering Sea (SEBS) pelagic ecosystem. Alternating climate states influence the survival of walleye pollock through bottom-up control of zooplankton communities and possible top-down control of predator abundance. Quantifying the seasonal progression and spatial trends in energy content of walleye pollock provides critical information for predicting overwinter survival and recruitment to age-1 because age-0 walleye pollock rely on energy reserves to survive their first winter. Age-0 and age-1 walleye pollock were collected in the SEBS from May to September 2008–2010. Energetic status was determined through quantification of energy density (kJ/g) and proximate composition (i.e., % lipid, % moisture) with variation in energy density primarily driven by variability in % lipid. Energy densities remained relatively low during the larval phase in spring, consistent with energy allocation to somatic growth and development. Lipid acquisition rates increased rapidly after transformation to the juvenile form (25–40mm standard length), with energy allocation to lipid storage leading to higher energy densities in late summer. This transition in energy allocation strategies is a physiological manifestation of survival constraints associated with distinct ontogenetic stages; a strategy favoring growth to escape size-dependent predation appears limited to larval development while juvenile fish allocate proportionally more mass to lipid storage in late summer. We propose that the time after the end of larval development and before the onset of winter represents a short critical period for energy storage in age-0 walleye pollock, and that overwinter survival depends on accumulating sufficient stores the previous growing season and consequently may be an important determinant of recruitment success.

Seasonal variations of belowground carbon transfer assessed by in situ <sup>13</sup>CO<sub>2</sub> pulse labelling of trees

Abstract. Soil CO2 efflux is the main source of CO2 from forest ecosystems and it is tightly coupled to the transfer of recent photosynthetic assimilates belowground and their metabolism in roots, mycorrhiza and rhizosphere microorganisms feeding on root-derived exudates. The objective of our study was to assess patterns of belowground carbon allocation among tree species and along seasons. Pure 13CO2 pulse labelling of the entire crown of three different tree species (beech, oak and pine) was carried out at distinct phenological stages. Excess 13C in soil CO2 efflux was tracked using tuneable diode laser absorption spectrometry to determine time lags between the start of the labelling and the appearance of 13C in soil CO2 efflux and the amount of 13C allocated to soil CO2 efflux. Isotope composition (δ13C) of CO2 respired by fine roots and soil microbes was measured at several occasions after labelling, together with δ13C of bulk root tissue and microbial carbon. Time lags ranged from 0.5 to 1.3 days in beech and oak and were longer in pine (1.6–2.7 days during the active growing season, more than 4 days during the resting season), and the transfer of C to the microbial biomass was as fast as to the fine roots. The amount of 13C allocated to soil CO2 efflux was estimated from a compartment model. It varied between 1 and 21 % of the amount of 13CO2 taken up by the crown, depending on the species and the season. While rainfall exclusion that moderately decreased soil water content did not affect the pattern of carbon allocation to soil CO2 efflux in beech, seasonal patterns of carbon allocation belowground differed markedly between species, with pronounced seasonal variations in pine and beech. In beech, it may reflect competition with the strength of other sinks (aboveground growth in late spring and storage in late summer) that were not observed in oak. We report a fast transfer of recent photosynthates to the mycorhizosphere and we conclude that the patterns of carbon allocation belowground are species specific and change seasonally according to the phenology of the species.

Absconding Behavior and Management of Apis cerana F. Honeybee in Chitwan, Nepal

Twelve colonies of five-framed Apis cerana F. with about equal brood, hive storage and colony strength were prepared in November 2004 and the colony development parameters recorded. One-third of the colonies absconded in summer and about one-sixth in rainy season, while non-absconded colonies also slowed comb building, brood rearing, colony strength and hive storage in summer and rainy seasons. Feeding sugar candy and pollen substitute prevented absconding in May and July. Three weeks feeding in May resulted higher comb building (15.0%), higher brood rearing (158.8%), stronger colony strength (15.0%) and higher hive storage (171.2% honey, 270.9% pollen) in June. Those colonies having higher brood mite (Varroa jacobsoni Oud.) in winter absconded earlier. 
 
 Key words: Apis cerana, absconding, brood mite, pollen substitute, colony management 
 
 J. Inst. Agric. Anim. Sci. 27:77-86 (2006)

H-29 パッケージ型空調機の躯体蓄熱空調システムへの適用検討 : (その2) 事務所ビルにおける夏期実測結果

H-29 パッケージ型空調機の躯体蓄熱空調システムへの適用検討 : (その2) 事務所ビルにおける夏期実測結果

Heterothermy and the water economy of free-living Arabian oryx (Oryx leucoryx).

To test the idea that large, free-living, desert ungulates use heterothermy to reduce water loss, we measured core body temperature (T(b)) of six free-ranging, adult Arabian oryx (Oryx leucoryx) during 2 years in the arid desert of west-central Saudi Arabia. We report the first case of heterothermy in a free-living ruminant in a desert environment: T(b) varied by 4.1+/-1.7 degrees C day(-1) during summer (June to September) and by 1.5+/-0.6 degrees C day (-1) during winter (November to March). Over both seasons, mean T(b) was 38.4+/-1.3 degrees C. During the day in both summer and winter, T(b) increased continually, suggesting that oryx store heat instead of dissipating it by evaporation, whereas at night T(b) decreased. The minimum T(b) was lower in summer (36.5+/-1.16 degrees C) than in winter (37.5+/-0.51 degrees C) despite the fact that the temperature gradient between T(b) and air temperature (T(a)) was larger and solar radiation was lower in winter. Throughout the year, daily variation in T(b) appeared to reflect thermal load (T(a,max)-T(a,min)) rather than an endogenous rhythm. Behavioural thermoregulation was used by oryx to cope with thermal stress during summer: animals lay down in shade in the morning shortly before T(a) exceeded T(b) and remained there until evening when T(b)-T(a) became positive. The use of heterothermy by oryx resulted in storage of 672.4 kJ day(-1) animal(-1) in summer and 258.6 kJ day(-1) animal(-1) in winter, if heat storage is based on calculations involving mean T(b). To dissipate this heat by evaporation would require 0.28 litres H(2)O day(-1) animal(-1) and 0.11 litres H(2)O day(-1) animal(-1) in summer and winter, respectively. Without heat storage in summer, we estimated that oryx would have to increase their water intake by 19%, a requirement that would be difficult to meet in their desert environment. If heat storage was calculated based on the daily change in T(b) rather than on heat storage above mean T(b) then we estimated that oryx saved 0.538 litres H(2)O day(-1) animal(-1) during summer.

Carbon exchange of an old-growth eastern hemlock (Tsuga canadensis) forest in central New England.

Carbon (C) exchange of an approximately 200-year-old eastern hemlock (Tsuga canadensis L.) forest in central Massachusetts, USA, was estimated from mid-October 2000 through October 2001 based on eddy covariance measurements and statistical modeling from microclimatic data. Measurements were made in 68% of the hours during the year of study, with > 50% coverage in all months except December and August. Data were filtered by wind direction and atmospheric turbulence to remove invalid measurements. Analysis of filtered data showed that photosynthetically active radiation (PAR) was significant in predicting C exchange, except during the winter. Daily minimum air temperature affected C exchange in autumn and winter, whereas time of day, water vapor pressure deficit and air temperature had significant effects on C storage in spring, summer and fall. Most C storage in the stand occurred in April through July and in October 2001, with maximum rates in April and May. Persistent cold weather prevented C storage in December through March. In early spring 2001, C uptake was sensitive to nocturnal frost: daily minimum air temperatures below 0 degrees C reduced C fixation, and minima below -5 degrees C caused its virtual cessation. Soil temperature was a poor predictor of C balance during this period. In August, high soil and air temperatures (averaging 16.7 and 21.1 degrees C, respectively) drove high ecosystem respiration, which approximately balanced C uptake. These patterns show potential for stimulated C storage in hemlock forests in a warmer climate with fewer spring and autumn frosts, but reduced C storage during warmer summers. Estimated annual C storage was 3.0 Mg ha(-1), which is higher than for younger coniferous and deciduous forests during earlier years in the northeastern USA. Long-term data are needed to determine if the estimated high C storage in this hemlock forest is a result of interannual climate variation or an effect of forest composition.

Fine‐tuned travel planning for hazardous journeys

Few recent research papers radiate the feeling of largescale geographic and biological coherence and synthesis typical of Moreau’s (1972) seminal book on the migration of landbirds between Eurasia and Africa. A study in this direction, however, is that by Rubolini et al. (2002) on barn swallow Hirundo rustica fuelling patterns before southward migration published in this issue of the Journal of A ian Biology. Within the context of the Europe-wide ‘EURING Swallow Project’, Rubolini and co-workers describe the increases in body mass and fat score from late August to early October in barn swallows at 19 roost sites in Spain and Italy. In both first-year and older birds there were consistent differences in body mass and fat score between Spain and Italy, with the birds captured at Spanish roost sites showing smaller maximum fuel stores than the birds in Italy. Consistent with the assumption that barn swallows left the areas of the roost site for southbound long-distance flights across both the Mediterranean Sea and the Sahara, the authors found a positive correlation between the amount of fuel stored at each of the sites and the lengths of the ensuing flight across the two presumed ecological barriers. That the correlation between fuel stores and distance was weaker when calculated for a crossing of the Mediterranean only, was taken as evidence for the fact that after leaving the stopover areas in Spain and Italy, barn swallows do little feeding in North Africa before crossing the Sahara (Fig. 1). Given that swallows would in principle be able to feed on aerial arthropods while in migratory flight, many of us have assumed that aerial foragers do not face ecological barriers to the same extent as specialised landand waterbirds. As a consequence, aerial foragers would not need to build up fuel stores to the same extent, something that would come handy given all the ecological costs associated with such stores (Witter and Cuthill 1993). An earlier finding that barn swallows in north-western Europe show rather little fuel storage in late summer (Ormerod 1989) seemed to confirm this preconception. However, it has been found that barn swallows carry substantial fuel stores prior to a Sahara crossing, both in Algeria (Bairlein 1988) and in Italy (Pilastro and Magnani 1997). The new study of Rubolini and co-workers adds importantly to the story not only by confirming that fuelling takes place, but also by showing that the total fuel store deposited at any one site seems to be a function of the width of the barrier ahead. That the relatively hospitable North African rim can be considered part of an ecological barrier for barn swallows during southward migration, comes as a surprise. Another surprise is that barn swallows at the northernmost sites apparently initiated the big jump from farther away than seemingly necessary. To accomplish this they put on more fuel. This runs contrary to the finding by Pilastro and Spina (1997) in their exciting interspecific comparison of residual fuel stores of birds that have crossed the Sahara in spring. The fuel stores

Energy Storage and Utilization Patterns of Gizzard Shad in Acton Lake, Ohio

Abstract Seasonal changes in dry body weight and caloric and lipid contents were studied in ages 0 and I and ages I and II gizzard shad (Dorosoma cepedianum) in 1973 and 1974, respectively. Dry body weight increases were best described by second and third order polynomial equations, with maximum values occurring in late autumn. Data on body caloric and lipid contents indicated a period of rapid storage in late summer and early autumn. Declines in average dry body weight, body calories, and body lipids occurred during the winter months. The intensity of the fattening process was greater in age-I fish than in ages 0 and II fish. The highest values of body lipids (30% of dry weight) and calories (6,909 cal/g ash-free dry weight) were observed in age-I fish on 16 November and 20 November 1973, respectively. Lipid reserves were mobilized during over-wintering and, in age-II fish, during the reproductive cycle. Energy reserves may also be utilized for body maintenance and growth when reductions occur in the ava...

Mineral Metabolism of Aged Persons in the Prevailing Area of Cerebrovascular Lesions, With Special Reference to Calcium, Magnesium, Phosphor and Nitrogen

Seasonal variations of mineral metabolism of calcium, magnesium, phosphor and nitrogen were examined for seven patients at a hospital and for 36 aged persons at a nursing home. Chemical analyses were made of food, feces and urine for 20 days period at the hospital and 5 days period at the nursing home in each season of summer and winter. And the balance between the intake and the excretion was compared between the two seasons. 1. As for calcium metabolism of the patients, the balance was higher in summer. And about the aged persons, both balance and storage seemed to be higher in summer. 2. Magnesium metabolism of the patients and also of the aged persons showed significantly higher level in summer from the view-points of the balance and the storage studies. 3. As for phosphorous metabolism, the patient group showed higher values in the balance and the storage in summer at the 5% level. However, the difference of these values of the aged persons between the two seasons did not reached to the significant level. 4. Nitrogen analyzed as an indication of protein metabolism showed positive balance in the two seasons for the hospital patients, and the storage rate was higher in summer with the significant level of 1%. For the asylum people the difference was not seen between the two seasons.

A Change of the Vitamin A Concentration Enriched to Fish Sausage during Storage in Summer

Fish sausage was fortified with concentrated fish liver oil with 5300I.U./100g. of vitamin A and stored under the two different conditions. One group of the samples was stored at room temperature in summer time and the other group was in refrigerator. These states were kept continued for 72 days. The estimation of vitamin A content of each sample had been made at two stages in preparation process and during the above storage period, it was estimated 5 times. The vitamin was estimated by colorimetric method using Carr-Price reaction. The results were shown in table 1 and 2. As seen in the table, the remained vitamin A concentration of each sample was 73% before boiling. After boiling, no change in the value was recognized.The results of the estimation of vitamin A, which were carried out 5 times in all after the preparation of the samples, showed that the concentration of the vitamin A was not changed during 24 days' storage both in summer room temperature and in the refrigerator, but 72 days' storage brought about aconsiderable decrease in case of room temperature, though no change was observed in case of refrigerator.