Cold Temperature

The kinetics of the feed-to-glass conversion affects the waste vitrification rate in an electric glass melter. The primary area of interest in this conversion process is the cold cap, a layer of reacting feed on top of the molten glass. The work presented here provides an experimental determination of the temperature distribution within the cold cap. Because direct measurement of the temperature field within the cold cap is impracticable, an indirect method was developed in which the textural features in a laboratory-made cold cap with a simulated high-level waste feed were mapped as a function of position using optical microscopy, scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction. The temperature distribution within the cold cap was established by correlating microstructures of cold-cap regions with heat-treated feed samples of nearly identical structures at known temperatures. This temperature profile was compared with a mathematically simulated p...

Therapeutic hypothermia is commonly applied to limit ischemic injury in organ transplantation, during cardiac and brain surgery and after cardiopulmonary resuscitation. In these procedures, the kidneys are particularly at risk for ischemia/reperfusion injury (IRI), likely due to their high rate of metabolism. Although hypothermia mitigates ischemic kidney injury, it is not a panacea. Residual mitochondrial failure is believed to be a key event triggering loss of cellular homeostasis, and potentially cell death. Subsequent rewarming generates large amounts of reactive oxygen species that aggravate organ injury. Recent Advances: Hibernators are able to withstand periods of profoundly reduced metabolism and body temperature ("torpor"), interspersed by brief periods of rewarming ("arousal") without signs of organ injury. Specific adaptations allow maintenance of mitochondrial homeostasis, limit oxidative stress, and protect against cell death. These adaptations consi...

Background: Pelviureteric junction (PUJ) obstruction after renal transplantation is uncommon. Surgical correction can be technically challenging due to dense perinephric adhesions and variable hilar vascular anatomy. Endopyelotomy is well established in the treatment of PUJ obstruction in native kidneys. Methods: The present paper reports the first experience of antegrade visual cold‐knife endopyelotmy performed in a renal allograft. In orientating the incision at the PUJ, preoperative imaging was supplemented by intrarenal Doppler ultrasound, using a probe designed for transoesophageal cardiac monitoring. To the authors’ knowledge this approach has not previously been reported. Results: Renal vascular relationships were readily indentified by identifying arterial and venous waveforms. Conclusions: For this uncommon procedure the use of intrarenal Doppler ultrasound provides greater security in avoiding inadvertent vascular injury.

The lowland tropical rainforests in Xishuangbanna, Southwest (SW) China, mark the northern limit of Asian tropics. Fog has been hypothesized to play a role in maintaining rainforests and tropical crop production in this region, but the physiological mechanism has not been studied. The goals of this study were to characterize the seasonal dynamics in photosynthesis and to assess the potential for fog to mitigate chilling-induced photodamage for tropical trees and crops in Xishuangbanna. We measured seasonal dynamics in light-saturated net photosynthetic rate (Aa), stomatal conductance (gs), intercellular CO2 concentration, quantum yield of Photosystem II (Fv/Fm) and maximum P700 changes (Pm; indicates the amount of active PSI complex), as well as chilling resistance and fog (light/shading) effects on low temperature-induced decline in Fv/Fm and Pm for native tree and introduced lower latitude tree or woody shrub species grown in a tropical botanical garden. Despite significant decrea...

Establishment of anterior-posterior and dorsal-ventral polarity within the Drosophila egg chamber requires signaling between the germline and the somatic cells of the ovary. The gene gurken (grk) encodes a TGFoi-like protein that is localized within the developing oocyte and is thought to locally activate torpedo/Egfr (top/Egfr), the Drosophila homolog of the EGF receptor, which is expressed throughout the follicular epithelium surrounding the oocyte. grk-Egfr signaling is required early in oogenesis for specification of posterior follicle cell fate and later in oogenesis for dorsal follicle cell fate determination, thus establishing the axes of the egg shell and embryo. Previous studies have shown that these patterning processes are highly sensitive to changes in the levels and localization of grk mRNA. Here we show that post-transcriptional regulation of Grk protein levels is required for correct pattern formation. encore (enc), a gene that functions in the regulation of germline ...

Significance Survival strategies for overwintering insects rely on the biochemical components in body fluids, where trehalose and antifreeze proteins (AFPs) are sometimes the best-known and extensively studied carbohydrate and protein components occurring in winters in both freeze-tolerant (they can survive if frozen) and freeze-avoiding species (they die if frozen). AFPs are known to lower the freezing temperature and defer the growth of ice, whereas their roles in freeze-tolerant species have long been speculated. By examining the larval blood of a freeze-avoiding beetle, we reveal a new role for AFPs by demonstrating that AFPs effectively inhibit trehalose crystallization. This finding provides a novel approach for cold protection and for inhibiting trehalose crystallization in medical and industrial applications.

The blackbuck (Antilope cervicapra) is a small (20–30 kg) Indian antelope that is listed on Schedule I of the Indian Wildlife Protection Act, 1972. Studies were undertaken to develop assisted reproductive technologies, such as synchronisation of oestrus and non-surgical AI, to support the conservation and genetic management of this Indian antelope. Semen characteristics, testosterone levels and the feasibility of short-term cold storage of semen were investigated. Furthermore, different oestrous synchronisation protocols (norgestomet implants and prostaglandin injections) were evaluated for successful AI, defined as the birth of live young. Norgestomet ear implants and i.m. administration of pregnant mare’s serum gonadotropin (PMSG) resulted in successful pregnancies in two of five inseminated females, but both had twin pregnancies that were delivered prematurely. In contrast, two injections of prostaglandin 11 days apart were effective in synchronising oestrus in the blackbuck. Tra...

Thermal performance curves enable physiological constraints to be incorporated in predictions of biological responses to shifts in mean temperature. But do thermal performance curves adequately capture the biological impacts of thermal extremes? Organisms incur physiological damage during exposure to extremes, and also mount active compensatory responses leading to acclimatization, both of which alter thermal performance curves and determine the impact that current and future extremes have on organismal performance and fitness. Thus, these sub-lethal responses to extreme temperatures potentially shape evolution of thermal performance curves. We applied a quantitative genetic model and found that beneficial acclimatization and cumulative damage alter the extent to which thermal performance curves evolve in response to thermal extremes. The impacts of extremes on the evolution of thermal performance curves are reduced if extremes cause substantial mortality or otherwise reduce fitness...

Studies have typically used shifts in mean temperatures to make predictions about the biotic impacts of climate change. Though shifts in mean temperatures correlate with changes in phenology and distributions, other hidden, or cryptic, changes in temperature, such as temperature variation and extreme temperatures, could pose greater risks to species and ecological communities. Yet, these cryptic temperature changes have received relatively little attention because mean temperatures are readily available and the organism-appropriate temperature response is often elusive. An alternative to using mean temperatures is to view organisms as physiological filters of hourly temperature data. We explored three classes of physiological filters: (1) nonlinear thermal responses using performance curves of insect fitness, (2) cumulative thermal effects using degree-day models for corn emergence, and (3) threshold temperature effects using critical thermal maxima and minima for diverse ectotherms...

The poliovirus vaccine field is moving towards novel vaccination strategies. Withdrawal of the Oral Poliovirus Vaccine and implementation of the conventional Inactivated Poliovirus Vaccine (cIPV) is imminent. Moreover, replacement of the virulent poliovirus strains currently used for cIPV with attenuated strains is preferred. We generated Cold-Adapted Viral Attenuation (CAVA) poliovirus strains by serial passage at low temperature and subsequent genetic engineering, which contain the capsid sequences of cIPV strains combined with a set of mutations identified during cold-adaptation. These viruses displayed a highly temperature sensitive phenotype with no signs of productive infection at 37°C as visualized by electron microscopy. Furthermore, decreases in infectious titers, viral RNA, and protein levels were measured during infection at 37°C, suggesting a block in the viral replication cycle at RNA replication, protein translation, or earlier. However, at 30°C, they could be propagat...

Campomanesia adamantium (Myrtaceae) is popularly known as "gabiroba" and has been used in folk medicine as antirheumatic, antidiarrheal, hypocholesterolemic and anti-inflammatory. This study evaluated the anti-inflammatory and antinociceptive activities and toxicology of essential oils from peel (EOP) and seed (EOS) of C. adamantium fruits in animal models. Different groups were treated with doses of 100 and 300 mg/kg and the inflammatory parameters were evaluated in carrageenan induced paw oedema and leukocyte migration in pleurisy model, while antinociceptive activity was evaluated using formalin method in rodents. The major constituent of EOP and EOS was limonene with 13.07% and 20.89%, respectively. No clinical signs of toxicity have been observed in animals. It was observed a significant decreased (P<0.01) in leukocyte migration at the dose of 300 mg/kg of EOP and EOS, with maximal inhibition of 89±3% for EOP and 80±6% for EOS. Paw oedema was inhibited at all times...

The acquisition of reliable and meaningful photo-plethysmographic (PPG) signals using conventional pulse oxime-try technology may be compromised by conditions of low tissue perfusion. We have developed a novel 'trans-reflectance' PPG measurement system which combines reflectance and transmit-tance together into a single mode. For comparison purposes the system also enables the independent display of reflectance and transmittance PPG signals simultaneously. Preliminary experiments were performed on volunteers to assess the performance of the probe, where, artificial hypoperfusion was created in individuals and data was recorded with the newly developed trans-reflectance photoplethysmographic mode, and the conventional transmittance and reflectance PPG modes. The PPG signals recorded during hypoperfusion using the trans-reflectance mode were of good quality with higher signal-to-noise ratio than those obtained from the transmittance and reflectance modes.

INTRODUCTION: Mortality is associated with daily temperatures and extreme cold events. This study aimed to analyze the effects of low temperatures on mortality in the main urban areas of Argentina during 2005-2015. METHODS: A time-series study with
generalized additive models was conducted, modeling the relationship between low temperatures and mortality for 21 cities in Argentina between 2005 and 2015. Total mortality was analyzed as well as mortality by sex, age and cause of death, considering cold days, cold spells and delays of 7 and 14 days after those events. RESULTS: Within a 7-day lag, the risk of death increases for a cold day in half of the cities analyzed between 1.04 [CI95%: 1.00-1.08] and 1.14 [CI95%: 1.06-1.23]. The most vulnerable group was people aged 65 or more years, with increases of up to 1.20 [CI95%: 1.05-1.39]. Cold spells are associated with an increased risk within the subsequent 7 days in 8 cities (1.05
[CI95%: 1.03-1.08] to 1.30 [CI95%: 1.03-1.65]), which increases to 10 cities for the 14-day lag, with slightly lower values. CONCLUSIONS: With differences in magnitude and statistical robustness by cities, the population of most urban areas presents an increased risk of death within 7 and 14 days after an event of extreme cold.