Development of thermoregulation in Hawaiian brown noddies (Anous stolidus pileatus)

1. 1.|Oxygen consumption ( ) and body temperture (T_b) of Hawaiian brown noddies (Anous stolidus pileatus [Aves: Laridae]) during late incubation and in the first 24 h after hatching were measured at ambient temperatures (T_a) between 28 and 38°C and between 15 and 43°C, respectively. Evaporative cooling by hatchings at T_a of 36–43°C was also measured.

2. 2.|Throughout the late incubation stages studied, and T_b both varied directly with T_a in an ectothermic pattern.

3. 3.|The hatchlings successfully regulated T_b at T_a between ca. 29 and 43°C.

4. 4.|The functional basis of the abrupt increase in thermoregulatory capacity with hatching is discussed.

Daily rhythms of nonshivering thermogenesis and responses to photoperiod manipulations in Apodemus mystacinus from two different ecosystems

Comparative physiology is an important tool for understanding adaptation to environment. Regulatory nonshivering thermogenesis (NST) is an essential mechanism in small mammals for coping with low ambient temperatures. Because of its geographical location and its sharp climatic changes across short distances, Israel offers conducting comparative studies between different populations of the same species. The aims of this study were: (1) to compare NST-capacity daily rhythms, between the two populations of the broad-toothed field mouse Apodemus Mystacinus—that of Mount Carmel (Mediterranean) and that of Mount Hermon (Subalpinic), (2) to compare the thermoregulatory daily rhythms response to photoperiod manipulations of mice from the two populations.

Mice were acclimated for at least 3 weeks to long scotophase (16D:8L-LS) and then to long photophase (16L:8D-LP) at a constant ambient temperature (T_a) of 24±1 °C. The following variables were compared at four different times of the day (06, 12, 18, 24 h): minimal body temperature (T_bMin), minimal oxygen consumption (VO₂Min) measured at the lower critical point and their response to noradrenaline (NA), 1.5 mg/1 kg.W_b injected s.c., (VO₂NA and T_bNA). NST-capacity was calculated as the ratio between VO₂NA and VO₂Min. The measurements were carried out at T_a of 28 °C and in light conditions matching those of acclimation. NA was injected after establishing VO₂Min and T_bMin. The values mean±SD are given for each measurement for n=6.

A three-way ANOVA revealed a significant difference between the two populations. Significant differences were revealed at different hours within populations under the different photoperiod regimes for different measured variables.     

The importance of microhabitat in thermoregulation and thermal conductance in two namib rodents—a crevice dweller, Aethomys namaquensis, and a burrow dweller, Gerbillurus paeba

1. 1.|Thermoregulatory measurements of two Nambi rodents; Gerbillurus paeba, a burrow dweller, and Aethomys namaquensis, a crevice dweller were compared. Both were similar to other small arid-adapted rodents in that basal metabolic rates were reduced, thermoneutral zones narrow and evaporative water losses low. Rates of conductance and thermal lability, however, at ambient temperatures (T_a) below thermoneutral zone, were significantly different (P 0.01).

2. 2.|The rock rat A. namaquensis, living in a microclimate characterized by a large diel range and low humidities, compensates for a reduced basal metabolic rate by having a low rate of conductance. In this way it maintains precise thermoregulatory control. G. paeba, on the other hand, living in a thermally-stable milieu, does not control body temperature precisely. This animal instead utilizes a high rate of conductance to remove metabolic heat produced within the body. This would be advantageous to an animal living in a plugged burrow where the high humidities encountered impede the rate of evaporative cooling.

3. 3.|The energetic responses of both species, above the thermoneutral zone, appear to reflect very closely the environmental conditions which occur in the microhabitat that they rest in during the day. G. paeba shows less tolerance to temperature fluctuations than A. namaquensis, but shows more marked increases in short-term cooling mechanisms at high T_as.

4. 4.|Despite the increased use of evaporative cooling through salivation and panting in addition to pulmocutaneous evaporation, exposure to T_as above 38°C is rapidly lethal to G. paeba.

Phase equilibria and gelation in gelatin/maltodextrin systems — Part I: gelation of individual components

As a prelude to studies of co-gelation with galatin, the gelation behaviour of Paselli maltodextrins SA-6 and SA-2 (DE ≈ 6 and 2, respectively) was mapped out over the experimentally-accessible range of temperature (T) and concentration (c), using a simple visual method to determine the time required for formation of a self-supporting network (t_g). For both samples, log t_g decreased linearly with log c and increased linearly with T. At equivalent temperatures and concentrations, SA-2 gelled between 20 and 60 times faster than SA-6.

Selected samples were monitored more rigorously by mechanical spectroscopy, taking t_g as the time at which elastic response (G′) became greater than viscous response (G″). In all cases the values of t_g obtained by this procedure were lower than those from visual inspection, by a constant factor of about 3·4.

The concentration-dependence of gel moduli (G′) for SA-2 and for gelatin (second-extract limed ossein; LO-2) fitted accurately to the form anticipated from cascade theory for normal polymer networks. For SA-6, by contrast, log G′ varied linearly with log c over the entire range at which measurements could be made, indicating a different mechanism of structure-formation (such as the agglomeration of short, aggregated helices).     

Trametes sp. LS-10C固态发酵产漆酶培养基优化及其对双酚A的降解

漆酶是一种绿色高效的多酚氧化酶,在降解双酚A方面具有巨大潜力。为降低发酵产漆酶的成本及考察漆酶在双酚A降解中的能力,本研究以麸皮和柚皮为主要基质,优化了栓菌固态发酵产漆酶条件,对优化后获得的漆酶在双酚A降解中的应用进行了研究。结果表明,在培养基组分为：麸皮和柚皮粉比例为6:4（W/W）、固液比1:2.5（W/V）、铜离子2%（W/W）、蔗糖3%（W/W）、硝酸钾2%（W/W）、稻壳20%（W/W）的条件下,栓菌发酵产漆酶的酶活最高,发酵11d后,酶活可达到38.4U/gds。当双酚A初始浓度为10μg/mL时,在55℃条件下酶解140min后,双酚A基本降解完全。     

Application of the hydro(solvo)thermal technique to the synthesis of metal carbonyl chalcogenide clusters Part 3. Synthesis, structural characterization, and spectroscopic studies of the clusters [{M(CO)4}n(MS4)] (M = Mo, W; N=1, 2)

The methanothermal reactions of M(CO)₆ (M = Mo, W) with Na₂S₂ gave a series of homonuclear clusters [{M(CO)₄}_n(MS₄)]²⁻ (M=Mo, W; N=1, 2), i.e. (Ph₄P)₂[(CO)₄Mo(MoS₄)] (I), (Ph₄P)₂[(CO)₄W(WS₄)] (II), (Ph₄P)₂[(CO)₄Mo(MoS₄)Mo(CO)₄] (III) and (Ph₄P)₂[(CO)₄W(WS₄)W(CO)₄] (IV). The two dimers, I and II, as well as the two trimers, III and IV, are isostructural to each other, respectively. All compounds crystallize in the triclinic space group with Z=2. The cell dimensions are: a=12.393(8), b=19.303(9), c=11.909(6) Å, =102.39(5), β=111.54(5), γ=73.61(5)°, V=2522(3) ų at T=23 °C for I; a=12.390(3), b=19.314(4), c=11.866(2) Å, =102.66(2), β=111.49(1), γ=73.40(2)°, V=2511(1) ų at T=23 °C for II; a=11.416(3), b=22.524(4), c=10.815(4) Å, =91.03(2), β=100.57(3), γ=88.96(2)°, V=2733(1) ų at T=−100 °C for III, a=11.498(1), b=22.600(4), c=10.864(3) Å, =90.92(2), β=100.85(1), γ=88.58(1)°, V=2771(2) ų at T=23 °C for IV. The dimers are each formed by the coordination of the tetrathiometalate as a bidentate chelating ligand to an M(CO)₄ fragment while addition of another M(CO)₄ fragment to the dimers results in the trimers. All compounds contain both tetrahedral and octahedral metal centers with the formal 6+ and 0 oxidation states, respectively.     

Thermal responses of the fresh water turtle Mauremys caspica to step-function changes in the ambient temperature

1. 1.|The turtle Mauremys caspica cools significantly faster than it heats in air. The heating/cooling ratio is 0.49.

2. 2.|The variation of body temperature in relation to time-course in response to a step-function change of environmental temperature, fitted to a second-order system improves that of a first-order system.

3. 3.|The gradient between ambient temperature (T_a) and equilibrium body temperature (T_b) increases significantly and progressively when ambient temperature rises over 25°C.

4. 4.|At 40°C thermoregulatory hyperventilation was detected, implying an increase in air convection requirement (ventilation relative to O₂ consumption, ).

渭河平原农田冬小麦土壤呼吸及其影响因素

基于对半湿润易旱区的渭河平原农田2013—2014年冬小麦生长期土壤呼吸(SR)及环境因子和生物因子的观测,研究了冬小麦土壤呼吸日变化、季节变化特征,综合分析了温度(T)、土壤含水量(W)、总初级生产力(GPP)和叶面积指数(LAI)对土壤呼吸的影响.结果表明: 冬小麦土壤呼吸日变化呈单峰型,呼吸速率变化范围为1.5～6.94 μmol CO₂·m^-2·s^-1,最大值出现在12:00—14:00;温度是影响土壤呼吸日变化的驱动因子,其中地表温度(T_s)能解释土壤呼吸时间变异的80.9%;土壤呼吸速率与温度的昼夜变化对应关系呈顺时针近椭圆曲线.冬小麦土壤呼吸速率从出苗后到冬季呈下降趋势,在冬季时保持较低水平,进入返青期后迅速增加,在抽穗期和灌浆期达到最大,成熟期后有所下降,变化范围为0.65～4.85 μmol CO₂·m^-2·s^-1;土壤呼吸季节变化与温度、土壤含水量、GPP、LAI均呈显著(P<0.01)正相关关系;土壤温度和水分是影响土壤呼吸季节变化的关键因素,使用复合模型SR=e^{(a+bT_{5 cm}}+cW10 cm+dW_{10 cm²}),可以解释土壤呼吸时间变异的82.6%,比单因子模型(不超过65.7%)的解释能力显著提高.经模型计算,该区域2013—2014年冬小麦生长期平均土壤呼吸速率为1.67 μmol CO₂·m^-2·s^-1.     

Influence of spent brewer’s yeast β-glucan on gelatinization and retrogradation of rice starch

The effects of β-glucan (BG) prepared from spent brewer’s yeast on gelatinization and retrogradation of rice starch (RS) were investigated as functions of mixing ratio and of storage time. Results of rapid visco-analysis (RVA) indicated that addition of BG increased the peak, breakdown, setback, and final viscosities, but decreased the pasting temperatures of the rice starch/β-glucan (RS/BG) mixtures. Differential scanning calorimetry (DSC) data demonstrated an increase in onset (T_o), peak (T_p), and conclusion (T_c) temperatures and a decrease in gelatinization enthalpy (ΔH₁) with increasing BG concentration. Storage of the mixed gels at 4 °C resulted in a decrease in T_o, T_p, T_c, and melting enthalpy (ΔH₂). The retrogradation ratio (ΔH₂/ΔH₁) and the phase transition temperature range (T_c − T_o) of the mixed gels increased with storage time, but this effect was reduced by the addition of BG. BG addition also slowed the syneresis of the mixed gels. Results of dynamic viscoelasticity measurement indicated that the addition of BG promoted RS retrogradation at the beginning and then retarded it during longer storage times. The added BG also retarded the development of gel hardness during refrigerated storage of the RS/BG mixed gels.     

Xanthan–galactomannan interactions as related to xanthan conformations

The influence of xanthan conformation on the physicochemical behaviour of their mixtures with galactomannan from Schizolobium parahybae mannose:galactose ratio (M/G=3), was studied by viscoelastic measurements, differential scanning calorimetry (DSC) and chiroptical (circular dichroism) methods. The results suggested a more effective interaction of the galactomannan with disordered xanthan segments, which are more abundant in low salt concentrations but are still present in lower proportion at temperatures lower than the temperature of xanthan conformational transition (T_m). The dependence of ellipticity with temperature in a circular dichroism (CD) spectra suggested an ordering of the xanthan chains induced by galactomannan at the temperature of gel formation (T_g≈25°C), under conditions where xanthan alone exhibits a disordered conformation. The lower T_g value found (≈25°C) compared with that (60°C) usually described in the literature is certainly related to the M/G ratio and the galactosyl unit distribution along the mannan main chain.     

两种不同来源的绿色木霉降解木质纤维素研究

利用纤维素酶高产菌绿色木霉Trichoderma viride降解木质纤维素是实现废料资源化的重要手段。本研究选取来自不同生境的两株T. viride,分别以玉米秸秆和甘草药渣为基质,测定两者滤纸纤维素酶（filter paper cellulase,FPase）活性和还原糖产量。从时间、温度、水分、pH 4个方面比较两株T. viride的环境适应性和不同基质的差异性。结果表明,以玉米秸秆为基质,T. viride XJ最适初始料液比为1:4-1:5.5,T. viride AG最适初始料液比为1:5-1:5.5。初始料液比1:5.5时,T. viride AG产FPase活性显著高于T. viride XJ。两株T. viride最适发酵温度均为28℃,各温度处理下不同菌株间无显著差异。两株T. viride均表现为还原糖消耗。以甘草药渣为基质,T. viride XJ最适初始料液比为1:2-1:2.5,T. viride AG最适初始料液比为1:3-1:3.5。料液比高于1:3,T. viride AG产FPase活性显著高于T. viride XJ。T. viride AG最适发酵温度为28℃,T. viride XJ最适发酵温度为23-28℃。温度低于28℃,T. viride XJ产FPase活性显著高于T. viride AG。两株T. viride均表现为还原糖积累。两株T. viride最适初始pH均为6-7,最适发酵时间均为3d。最优发酵条件下FPase活性：T. viride AG>T. viride XJ。对T. viride产FPase诱导能力：甘草药渣>玉米秸秆。变差分解表明两株T. viride产FPase活性差异主要源于菌株对生境的生态适应。比较分析菌种来源、基质类型、环境条件对T. viride发酵效果的影响,将有助于该菌大规模应用性研究。     

Day-night variation of thermoregulatory responses to intraperitoneal electric heating in rats

1. 1.Hypothalamic temperature (T_hy), nonevaporative heat loss (R + C + K), evaporative heat loss (E), thermal conductance (k), metabolic heat production (M) and heat storage (S) of rats were simultaneously measured by direct and indirect calorimetry during internal heat loading (2 W per rat) with an intraperitoneal electric heater.

2. 2.The tests were made twice a day; once during the day (1000–1200 h) and once at night (2200–2400 h) at an ambient temperature of 24°C.

3. 3.The resting values of T_hy, colonic temperature, (R + C + K), E, M and heart rate, and the T_hy threshold for tail skin vasodilation (T_th) during internal heat load were significantly higher at night than during the day.

4. 4.The slopes showing the relationshiop between (R + C + K), k or M and T_hy were significantly steeper during the day than at night after T_hy exceeded T_th.

5. 5.The slopes showing the relationship between E or S and T_hy were not different during the day and at night.

6. 6.These results indicate that the responses of nonevaporative heat loss and heat production to internal heat load vary with the time of day in rats.

大兴安岭主要森林类型林分空间结构优化模拟

以大兴安岭地区4种主要林型[天然落叶松纯林(LF)、天然白桦纯林(BF)、针阔混交林(CBMF)和针叶混交林(CMF)]的1 hm²固定样地调查数据为基础,选择常用林分空间[混交度(M)、大小比数(U)、角尺度(W)、竞争指数(CI)]和非空间结构参数[林分生长活力(DC)、林木稳定性(DH)],并结合熵值-AHP赋权法,构建单木综合抚育采伐指数(T),运用Excel VBA编制模拟抚育采伐过程;系统比较各林型不同抚育采伐强度(分别为10%、20%和30%)下T值,并确定各林型的最优抚育采伐强度.结果表明:初始状态下,各林型平均W均为0.57,属于典型聚集分布;各林分平均U在0.50～0.51,林木整体生长的优势程度处于典型的中庸状态;各林分平均M整体较低,其中,混交林明显大于纯林;林分内平均CI大于2.0,林木生长竞争压力较大;LF整体稳定性、活力均显著高于其他林分;整体来说,BF的经营迫切性程度显著高于其他林分.从同一林型内相邻抚育采伐强度间的T值增长率来看,LF的最佳抚育采伐强度为30%,其余3种林型的最佳抚育采伐强度均为10%,T值增长率分别为9.7%、7.9%、6.6%和3.9%;而从不同林型下T值大小和郁闭度来看,BF的最佳抚育采伐强度为20%,其余林型的最优抚育采伐强度均为30%,此时T值分别提高了28.9%、16.4%、17.5%和9.2%.抚育采伐后林分整体结构得到不同程度的改善,其中,林分M显著增大,林木水平空间分布格局趋向随机分布,优势树种优势程度增加,样地内林木竞争压力明显减小,DC略有降低,DH得到提升.     

Temperature dependence of the germination of tomato seeds

1. 1.|The germination of tomato “C38” seeds exposed to periodical white incandescent light occurs from 6.0° ± 0.2°C to 37.5° ± 0.2°C, being rate-limited for 10.3° T 25.9°C, and elsewhere limited by the germination capacity.

2. 2.|Rate averages are linearly T-dependent outside their optimum range (25.9° T 29.5°C) and rate variances are typically heterogeneous.

3. 3.|The smooth curvilinear Arrhenius plot indicates that diffusion processes cannot be rate-limiting outside the interval 25.9° T 29.5°C, whereas phase transitions and (or) transconformation of proteins may limit the rate above 34.9°C and, by opposite effects, below 15.3°C.

4. 4.|The thermal communication between the environment and the germinating seed proceeds by a temperature signal which is quenched by random thermal noise at T 11.2°C and at T 34.0°C.

Physio-chemical properties of polymyxan 88A–water system

The system exopolysaccharide polymyxan 88A–water was studied at several temperatures. The temperature dependence of viscosity at cooling and heating was obtained in order to estimate the phase separation temperature (T_s) and the gelation temperature (T_g). The experimental values of T_s and T_g were used to plot the phase diagram of the system under study at polymer concentrations below 1.5 wt%. Viscous flow in the system was examined by the cylinder–cylinder rotation method. It has been found that: (i) at shear rates within 1–100 s⁻¹ the dependence of viscosity on shear rate can be fairly expressed by the power low; (ii) the activation enthalpy of viscous flow practically does not depend on shear rate; and (iii) the activation entropy of viscous flow is negative, most likely due to an orienting action of mechanical field.     

4种槭树叶功能性状及其关系对季节变化的响应

以牡丹江地区的白牛槭（Acer mandshuricum）、茶条槭（Acer tataricum subsp. ginnala.）、糖槭（Acer saccharum）、五角槭（Acer pictum subsp. mono）4种槭树为研究对象,分别于春季、夏季和秋季进行取样,测定叶片性状指标（叶厚度、气孔长度、气孔宽度、气孔密度、叶脉密度、比叶面积及色素质量分数）,分析叶片各性状的季节变化趋势,并探讨色素与叶性状间在不同季节下的关系。结果如下（：1）4种槭树均表现为在夏季具有较高的叶厚度、较低的比叶面积和气孔密度,在秋季具较高的比叶面积和叶脉密度、较低的叶厚度。（2）4种槭树均为在夏季有较高的叶绿素a、b,在秋季色素质量分数均降低,季节变化区间分别为叶绿素a 77.40%～98.80%,叶绿素b 85.60%～99.53%,类胡萝卜素4.29%～78.52%。（3）色素与叶性状关系密切,季节动态下色素与比叶面积、气孔密度、叶脉密度正相关,与叶厚度、气孔长度、气孔宽度负相关（P<0.05）,但不同季节相关性略有差异。4种彩叶植物的叶片在应对不同季节的气候条件时形成了不同的构建策略...     

Phase equilibria and gelation in gelatin/maltodextrin systems — Part IV: composition-dependence of mixed-gel moduli

The storage moduli (G′) of phase-separated co-gels formed by quench-cooling mixed solutions of gelatin and potato maltodextrin (Paselli SA-2 and SA-6) have been related quantitatively to the experimentally-determined concentration-dependence of G′ for the constituent polymers. Distribution of water between the phases was examined explicitly by using polymer blending laws to derive calculated moduli for gelatin-continuous and maltodextrin-continuous networks over the entire range of solvent partition. Allowance was made for the direct contribution of polymer chains, and for density differences between the phases, in calculating relative phase-volumes. The effect of gel formation prior to phase-separation was calculated using classical theory for network de-swelling. Good agreement with observed moduli for more than 30 gelatin/maltodextrin combinations was achieved using a single adjustable parameter, p (the ratio of solvent to polymer in the gelatin phase divided by the same ratio for the maltodextrin phase), with an optimum value of p ≈ 1·8 for both SA-6 and SA-2.     

Ambient temperature limits and stability of temperature regulation in telemetered male and female rats

Knowing the ambient temperature (T_a) limits of normothermia in laboratory rodents is important because their thermoregulatory responses are useful in studies of physiology, pharmacology and toxicology. The present study assessed the T_a limits of normothermia using radiotelemetry to monitor core temperature (T_c), heart rate (HR), and motor activity (MA) in unrestrained, male and female Long-Evans rats over a 24 h period. Rats were housed individually in acrylic cages with wire-screen tops and bottoms and maintained at T'_as ranging from 12 to 33.5°C for 24 h with food and water provided ad libitum on a 12:12 L:D photoperiod. The limits of normothermia (i.e. where there was no significant change in T_c) were <12–29.5°C for females and 14.5–29.5°C for males. T_c of males at T'_as of 12, 32, and 33.5°C increased significantly above the baseline T_c. Female rats had a lower T_c than males at the warmest and coldest T'_as. HR and MA were generally higher in females at all T'_as. Males appeared to be poorly adapted to thermoregulate at T'_as above 30°C as based on their excessively high T'_cs, low MA, and marked weight loss compared to that of the females. Within the limits of normothermia the stability of T_c regulation (i.e. [(ΔT_c/ΔT_a) × 100]/2) was ±1.3 and ± 0.9% for males and females, respectively, over a 24 h period. These data on the stability of T_c in the male and female rat provide a valuable framework to study the acute and chronic effects of drugs, chemicals and other agents that affect temperature regulation.     

Comparative aspects of the thermal biology of the short-tailed gerbil, Desmodillus auricularis, and the bushveld gerbil, Tatera leucogaster

1. 1. The response of oxygen consumption (VO₂), thermal conductance (C_d and C_min, body temperature (T_b), and evaporative water loss (EWL) of Tatera leucogaster and Desmodillus auricularis were measured over the range of ambient temperatures (T_a) from 5–35°C.

2. 2. Basal metabolic rate (BMR) of T. leucogaster was 0.841 ± 0.049 ml O₂ g⁻¹ h⁻¹ and lower than predicted, while that of D. auricularis was similar to the expected value (1.220 ± 0.058 ml O₂ g⁻¹ h⁻¹). D. auricularis had a high, narrow thermoneutral zone (TNZ) typical of nocturnal, xerophilic, burrowing rodents.

3. 3. D. auricularis and T. leucogaster regulated T_b over the range T_a = 5–35°C and kept EWL and dry thermal conductance at a minimum below the TNZ. However, the EWL of T. leucogaster increased rapidly above T_a = 30°C.

4. 4. After comparison with data from other species, it was concluded that there is an optimum size for xeric, nocturnal, burrowing rodents.

The combined effects of ambient temperature and enforced sustained swimming activity on body temperatures of arctic charr (Salvelinus alpinus L.)

1. 1.|The difference between tissue temperatures and ambient water temperatures (ΔT) of the ectothermic Arctic charr (Salvelinus alpinus L.) ranged between 0.2 and 0.6°C.

2. 2.|For fish held at 5.7°C there were no significant differences in ΔT of exercising fish and those of controls.

3. 3.|By contrast, for fish held at 1.7°C sustained exercise led to a significant increase in ΔT of all body compartments compared with fish held in standing water (controls).

4. 4.|It is suggested that Arctic charr are capable of a limited control of metabolic heat exchange between body compartments and surrounding water when subjected to sustained exercise and ambient temperatures <2°C.