Heat Lamp Research Articles

Impact of a long photoperiod during lactation on immune status of piglets1

The effects of a long photoperiod treatment around parturition and throughout lactation on immune status of piglets were studied. Sows were assigned to 2 light regimens: i) standard short photoperiod (SP, n = 17), 8 h of daily light from d 112 of gestation until d 23 of lactation; and ii) long photoperiod (LP, n = 17), 23 h of daily light from d 112 of gestation to d 4 of lactation and 16 h thereafter. In front of the crates, under the side heat lamps and behind the sow, light intensities were 59 ± 5, 109 ± 6, and 44 ± 6 lx, respectively. On d 15 of lactation and at weaning (d 23), 2 piglets of similar BW per litter were selected and immunized intramuscularly with ovalbumin (OVA). Blood samples (5 mL serum and 10 mL whole blood) were taken at d 15 and d 23 of lactation, and at d 30, 37, and 44 of age after weaning to evaluate the antibody response to OVA and measure phagocytosis, lymphocyte proliferative response, and different circulating blood lymphocyte populations of piglets. Results showed that phagocytosis was increased in piglets submitted to LP (P < 0.05). A treatment × time interaction (P < 0.001) indicated that SP piglets developed a better IgG response to OVA than LP piglets. The percentage of B lymphocytes was also increased (P = 0.02) in SP piglets compared with piglets exposed to LP during lactation; the lymphocyte response to OVA tended to be enhanced (P = 0.07) over time in SP piglets. Different subpopulations of CD8+ lymphocytes were markedly increased in SP piglets at 23 d of age compared with piglets exposed to LP (treatment × time: P < 0.05). These results suggest that exposure of piglets to LP during lactation seems to reduce the capacity of piglets to develop a strong immune response to novel antigens. This may have important consequences on the ability of piglets to resist an infection after weaning.

Development and characterization of polymer–ceramic continuous fiber reinforced functionally graded composites for aerospace application

Functionally graded materials (FGMs) have continuous change in the composition across the thickness which results in gradual change of the properties. The ability of the FGMs to perform more than one contrasting functions as an integral structure makes them an attractive material for aerospace applications. So far the research focus has been on the functionally graded coatings and particulate reinforced functionally graded composites. In this study, continuous fiber reinforced functionally graded composites (FGCs) have been prepared using quartz fabric reinforcement for thermo-structural aerospace application. Silicone resin and fused silica powder have been used to obtain graded matrix. The FGC laminates have been characterized for mechanical and thermal properties. The laminates were also evaluated for thermal shock resistance and thermal insulation properties by exposing to infra-red heating lamps under high heating rate of about 800°C/s and high heat flux of 0.6 Wmm−2 for 70 s. FGC laminates did not de-laminate or charred. Temperature drop across the laminate of 8 mm thickness was found to be 600°C. The concept of FGC fabrication process is demonstrated to fabricate scaled down typical airframe sections also.

Tetrasulfonated Poly(arylene biphenylsulfone ether) Block Copolymer and Its Composite Membrane Containing Highly Sulfonated Blocks

Among different types of fuel cells, proton exchange membrane (PEM) fuel cells show the highest power density and have been actively investigated for automobile applications. Although Nafion has been typically considered as a PEM for practical applications, there are still some limitations such as the high cost and the degradation of proton conductivity at high temperature (> 80 C). Several approaches have been examined to improve proton conductivity. The strategies have included changing the acidity and position of sulfonic acid groups and the control of membrane morphologies. Recently, highly sulfonated moieties or sequenced hydrophilic and hydrophobic groups as block copolymers were claimed to improve proton conductivity under high temperature. However, none of these alternative membranes could compete with Nafion membranes. Related to these reports, we wish to study the thermal and electrochemical properties and morphological characteristic of a block membrane enhanceing the number of sulfonic acid groups in a repeat unit of a polymer. Here, we report on highly sulfonated poly(arylene biphenylsulfone ether) block copolymer (5) made using tetrasulfonated 4,4'-bis[(4chloro-3-sulfonatophenyl)sulfony]biphenyl-2,2'-disulfonate (TsBCSBPD, 2) and its composite membrane using phosphotunstic acid (PWA). In the previous paper, we described the synthesis and characterization of tetrasulfonated poly(arylene biphenylsulfone ether) random copolymers made using TsBCSBPD (2). The block copolymer 4 was prepared as follows: First, hydrophobic oligomer 1 was made from 6F-BPA (4,4'-hexafluoroisopropylidene diphenol), DCDPS (4,4'-dichlorodiphenyl sulfone), and K2CO3 in dimethyl acetamide (DMAc). 7 Second, hydrophilic oligomer 3 was prepared from TsBCSBPD (2) and 6F-BPA in the same manner. Finally, we synthesized a block copolymer 4 from the hydrophobic 1 (Mw 10 kDa) and hydrophilic oligomer 3 (Mw 13 kDa) using a nuclephilic substitution reaction. This was then followed by hydrolysis with sulfuric acid (Scheme 1). The polymer had a high molecular weight (Mw 57 kDa), which supported the formation of a block structure. The H NMR spectrum of B37 copolymer is shown in Figure 1. H NMR analysis confirmed 37% sulfonation (the degree of sulfonation on each phenylene ring in the repeating unit). The B37 membrane was prepared by solution casting the acid form of the B37 copolymer in DMAc (10% w/v) and the B37-P30 (B37:PWA = 10:3, wt/wt) composite membrane was prepared by casting the acid form of the B37 and a commercial PWA (H3PWO40, Fluka Chemicals) in DMAc (10% wt/v). These castings were carried out onto a clean glass plate and then dried by a heat lamp at 80 C for 24 h. A summary of the thermal properties of the fabricated membranes is listed in Table 1. The TGA (thermogravimetric analysis) of B37, B37-P30, and Nafion N117 membranes

Treatment of Ivermectin Overdose in a Miniature Shetland Pony Using Intravenous Administration of a Lipid Emulsion

An 11-month-old miniature Shetland Pony colt weighing 26 kg was presented to the University of Zurich Equine Hospital for evaluation of acute onset of generalized seizures, followed by unconsciousness and recumbency, 34 hours after a massive (>25-fold) overdose of deworming paste (140 mg ivermectin and 1.05 g praziquantel). Instead of the labeled quantities of 0.2 mg ivermectin/kg and 1.5 mg praziquantel/kg, the foal had received the entire tube, equivalent to 5.4 mg ivermectin/kg and 40.4 mg praziquantel/kg. At presentation, the colt was in a stuporous condition but responded to pain stimuli including jugular venous catheter placement. Heart rate was 26/min, respiratory rate was 20/min, and rectal temperature was 34.5°C (94.1°F). The peripheral pulses were very weak and not detectable by palpation at all superficial arteries. Both jugular veins were poorly filled and capillary refill time was prolonged at approximately 3 seconds. The distal limbs and ears were cold to the touch. Palpebral and pupillary reflexes as well as menace responses were absent. In contrast, the corneal reflex was preserved and both eyes showed spontaneous horizontal nystagmus. Muscular tone of the tongue was decreased, whereas the anal reflex appeared normal. The clinical signs were most consistent with ivermectin intoxication. Ivermectin overdoses trigger severe neurologic signs by opening c-aminobutyric acid (GABA)-gated chloride channels, which in turn causes membrane hyperpolarization and blockade of neuronal impulses. In adult horses, no signs of intoxication are observed up to an ivermectin dosage of 1.8 mg/kg, whereas ingestion of 2 mg/kg has been shown to cause lethargy, ataxia, and visual impairment. The praziquantel overdose was considered less relevant in this foal, because praziquantel has a wide margin of safety, and the present exposure would result in only mild neurological and gastrointestinal signs. Analyses of blood samples at admission identified a low blood glucose concentration (3.4 mmol/L; normal, 3.6–6.1 mmol/L), normal plasma protein concentration (70 g/L; normal, 57–80 g/L) with low albumin (11 g/L; normal, 22–37 g/L) and increased globulin concentrations (59 g/L; normal, 27–50 g/L), a total bilirubin concentration of 9 lmol/L (normal, 9 –39 lmol/L), increased c-glutamyl transferase activity (GGT, 53 IU/L; normal, 5–24 IU/L), and low total calcium concentration (2.40 mmol/L; normal, 2.88– 3.55 mmol/L). Blood urea nitrogen and creatinine concentrations, as well as plasma sodium, potassium, and chloride concentrations, were within reference ranges. The blood lactate concentration was 2.3 mmol/ L (normal, <3 mmol/L). A CBC disclosed normocytic, normochromic anemia (hematocrit, 19.3%; normal, 30–42%; hemoglobin concentration, 7.0 g/dL; normal, 10.8–14.9 g/dL) with increased white blood cell count (WBC, 11.2 9 10/lL; normal, 4.7–8.2 9 10/lL). Treatment was initiated with warmed lactated Ringer’s solution (LRS) supplemented with glucose to a concentration of 2.5%, administered through a jugular venous catheter at a rate of 60 mL/kg/h. After 10 minutes, the blood glucose concentration had reached 8.3 mmol/L and treatment was continued with LRS without glucose at the same rate. After 1 hour, the fluid was changed to a maintenance crystalloid solution containing 1.5% glucose and the infusion rate was decreased to 4 mL/kg/h. By that time, peripheral pulse quality, jugular vein filling, and capillary refill time had improved, and the patient urinated. The colt was placed under a heat lamp, on a forced-air heating From the Equine Department, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland (Bruenisholz, Schwarzwald); the Institute of Pharmacology and Toxicology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland (Kupper, Muentener, Naegeli); and the Institute of Forensic Medicine, Faculty of Medicine, University of Zurich, Zurich, Switzerland (Dally, Kraemer). The analytical methods described herein were previously presented as a research abstract. Dally AM, Kupper JR, Bruenisholz H, et al. Determination of ivermectin in plasma of a mini Shetland Pony after poisoning using LC-MS/MS – effectiveness of intravenous lipid therapy. 12th International Congress of Therapeutic Drug Monitoring and Clinical Toxicology, Stuttgart, Germany, October 2–6, 2011. Corresponding authors: H. Naegeli, Prof. Dr. med. vet., Institute of Pharmacology and Toxicology; and C.C. Schwarzwald, PD Dr. med. vet., PhD, Dipl. ACVIM & ECEIM, Equine Department, Vetsuisse Faculty, Winterthurerstrasse 260, CH-8057 Zurich, Switzerland; e-mails: naegelih@vetpharm.uzh.ch and cschwarzwald@ vetclinics.uzh.ch. Submitted October 11, 2011; Revised November 4, 2011; Accepted November 29, 2011. Copyright © 2012 by the American College of Veterinary Internal Medicine 10.1111/j.1939-1676.2011.00865.x Abbreviations:

Effects of ambient temperature and early open-field response on the behaviour, feed intake and growth of fast- and slow-growing broiler strains

Increased activity improves broiler leg health, but also increases the heat production of the bird. This experiment investigated the effects of early open-field activity and ambient temperature on the growth and feed intake of two strains of broiler chickens. On the basis of the level of activity in an open-field test on day 3 after hatching, fast-growing Ross 208 and slow-growing i657 chickens were allocated on day 13 to one of the 48 groups. Each group included either six active or six passive birds from each strain and the groups were housed in floor-pens littered with wood chips and fitted with two heat lamps. Each group was fed ad libitum and subjected to one of the three temperature treatments: two (HH; 26°C), one (HC; 16°C to 26°C) or no (CC; 16°C) heat lamps turned on. Production and behavioural data were collected every 2 weeks until day 57. For both strains, early open-field activity had no significant effects on their subsequent behaviour or on any of the production parameters measured, and overall, the slow-growing strain was more active than the fast-growing strain. Ambient temperature had significant effects on production measures for i657 broilers, with CC chickens eating and weighing more, and with a less efficient feed conversion than HH chickens, with HC birds intermediate. A similar effect was found for Ross 208 only for feed intake from 27 to 41 days of age. Ross 208 chickens distributed themselves in the pen with a preference for cooler areas in the hottest ambient temperature treatments. In contrast, the behaviour of the slow-growing strain appeared to be relatively unaffected by the ambient temperature. In conclusion, fast-growing broilers use behavioural changes when trying to adapt to warm environments, whereas slow-growing broilers use metabolic changes to adapt to cooler ambient temperatures.

Roofing Assembly Simulated Heat and Light Test

Abstract The goal of this project is to search for a testing procedure for roof covering products that will radiate both heat and light onto a roof covering and then measure the impact that a given roof covering product has on heat transfer through the entire roofing assembly. Identical roof assemblies were built with ethylene propylene diene terpolymer (EPDM) rubber roof membrane over a wood deck. Sixteen heat lamps were positioned 1.14 m [45 in.] above the roof covering product to provide both heat and light. Thermocouples were placed on the underside of the wood deck and were insulated from outside air. The roofing assembly and the roof covering temperatures were brought to 18°C to 21°C prior to testing. Heat and light were radiated onto the roof coverings for 360 min and the under deck temperature was recorded at 1 min intervals for 600 min. Tested roof coverings included gravel, growing media, coatings, and panels in the form of concrete, ceramic foam, and rubber. The results of the tests have shown data similar to that which were recorded during warm, sunny days. As expected, the highest temperatures were achieved by the uncovered and uncoated black EPDM roof assembly. The temperature of this assembly diminished almost immediately upon the removal of the heat and light source. Thicker layers of growing media and ceramic foam block did not reach the peak temperature until several hours after the heat lamps were turned off. The roof assembly covered with reflective coating showed realistic resistance to the heat and light source. This is a significant advancement in the effort to provide equitable data for all roof coverings. The test provides a standard method of collecting data for traditional roof coverings as well as emerging technology roof covering materials to evaluate a roofing assemblies’ thermal performance from solar heat gain.

Assessment of the effects of changes in body temperature on cardiac electrophysiology in anaesthetised guinea pigs

IntroductionAnaesthetised guinea pigs are commonly used within Safety Pharmacology to evaluate drug effects on cardiac electrophysiology. However, anesthesia compromises the ability to thermoregulate, which can be further challenged when more invasive surgery is required. As anaesthetised animals are often used when screening for cardiotoxicity, thereby influencing go/no–go decisions, we wanted to quantify the impact of small temperature changes on the recorded electrophysiological parameters. MethodsMale guinea pigs were anaesthetised by pentobarbital, placed on a pre-heated table and a rectal thermistor inserted for monitoring of body temperature. After intubation animals were vagotomised and β-blocked, and lead II ECG needle electrodes attached. Following thoracotomy an atrial pacing electrode was attached and a suction MAP electrode positioned on the ventricular epicardium. In control animals temperature was kept constant (38.1±0.1°C) over the duration of the experiment. Animals in one group were slowly warmed to 41.9°C by a heating plate and a heating lamp, and in another group slowly cooled to 34.4°C by turning off all heating equipment. MAP duration at 90% repolarisation (MAPD90), AV conduction, ECG and body temperature were recorded during cardiac pacing every 5min up to 50min. ResultsNo time-dependent changes were seen in the control group. In contrast, a linear correlation was found between changes in body temperature and MAPD90, AV conduction, QTc and QRS intervals. For each degree temperature fell below 38°C MAPD90 was prolonged by 6.1ms, and for each degree above 38°C MAPD90 was shortened by 5.3ms. Corresponding changes were seen for QTc interval and AV conduction time, while effects on the QRS interval were smaller. DiscussionThe data highlights the importance of carefully controlling body temperature when performing electrophysiological recordings in laboratory animals. A change by a single degree can affect electrophysiological parameters by 5–10%, thus increasing the risk for a false positive or negative interpretation of cardiotoxicity.

Extreme winter warming events more negatively impact small rather than large soil fauna: shift in community composition explained by traits not taxa

AbstractExtreme weather events can have negative impacts on species survival and community structure when surpassing lethal thresholds. Extreme winter warming events in the Arctic rapidly melt snow and expose ecosystems to unseasonably warm air (2–10 °C for 2–14 days), but returning to cold winter climate exposes the ecosystem to lower temperatures by the loss of insulating snow. Soil animals, which play an integral part in soil processes, may be very susceptible to such events depending on the intensity of soil warming and low temperatures following these events. We simulated week‐long extreme winter warming events – using infrared heating lamps, alone or with soil warming cables – for two consecutive years in a sub‐Arctic dwarf shrub heathland. Minimum temperatures were lower and freeze‐thaw cycles were 2–11 times more frequent in treatment plots compared with control plots. Following the second event, Acari populations decreased by 39%; primarily driven by declines of Prostigmata (69%) and the Mesostigmatic nymphs (74%). A community‐weighted vertical stratification shift occurred from smaller soil dwelling (eu‐edaphic) Collembola species dominance to larger litter dwelling (hemi‐edaphic) species dominance in the canopy‐with‐soil warming plots compared with controls. The most susceptible groups to these winter warming events were the smallest individuals (Prostigmata and eu‐edaphic Collembola). This was not apparent from abundance data at the Collembola taxon level, indicating that life forms and species traits play a major role in community assembly following extreme events. The observed shift in soil community can cascade down to the micro‐flora affecting plant productivity and mineralization rates. Short‐term extreme weather events have the potential to shift community composition through trait composition with potentially large consequences for ecosystem development.

Cholecystokinin octapeptide induces hypothermia and improves outcomes in a rat model of cardiopulmonary resuscitation*

To investigate the effects of cholecystokinin octapeptide on thermoregulation, postresuscitation myocardial function, neurologic outcome, and duration of survival in a rat model of cardiopulmonary resuscitation. : Prospective, randomized, placebo-controlled experimental study. University-affiliated animal research laboratory. Ten male Sprague-Dawley rats. Ventricular fibrillation was induced and untreated for 6 mins. Defibrillation was attempted after 8 mins of cardiopulmonary resuscitation. Animal temperature was adjusted to 37.0 °C with the aid of a heating lamp. At 30 mins after resuscitation, animals were randomized to receive an intravenous injection of either cholecystokinin octapeptide (200 μg/kg in 0.3 mL saline) or vehicle placebo (0.3 mL saline). The ambient temperature settings and that of the distance of the heating lamp from the animal remained the same in both groups throughout the entire experiment. Body temperature, hemodynamic measurements, and postresuscitation myocardial function, including cardiac output, left ventricular ejection fraction, and myocardial performance index, were measured together with neurologic deficit scores and duration of survival. After injection of cholecystokinin octapeptide, blood temperature decreased progressively from 37.0 °C to 34.8 °C 5 hrs after resuscitation and returned to 37.0 °C at 9 hrs after injection. In the control group, blood temperature was sustained at 37.0 °C ± 0.2 °C during the same period of observation. Myocardial and neurologic function and duration of survival were significantly better in the cholecystokinin octapeptide-treated animals when compared to the control group. : In a rat model of cardiopulmonary resuscitation, cholecystokinin octapeptide induced mild hypothermia, attenuated postresuscitation myocardial dysfunction, and improved neurologic outcome and duration of survival.

Controlled Warming Effects on Wheat Growth and Yield: Field Measurements and Modeling

Climate warming may raise wheat (Triticum aestivum L.) yields in cooler climates and lower them in warmer climates. To understand these contrasting effects, infrared heating lamps were used to warm irrigated spring wheat by 1.5°C (day) and 3.0°C (night) above unheated controls during different times of the year at Maricopa, AZ. Changes in wheat growth with warming were used to test hypotheses for temperature effects on crop growth in the process model ecosys. Infrared heating substantially raised phytomass growth and grain yield under lower air temperature (Ta) following plantings from September through December. The same heating, however, lowered growth and yield under higher Ta following plantings from January through March. Gains in wheat yield of as much as 200 g C m−2 with heating under lower Ta were attributed in the model to more rapid CO2 fixation and to reduced chilling effects on seed set. These gains were only partially offset by losses from shortened wheat growth periods. Losses in wheat yield of as much as 100 g C m−2 with heating under higher Ta were attributed in the model to adverse effects of heating on crop water status and on CO2 fixation vs. respiration, to greater heat stress effects on seed set, and to shortened crop growth periods. Model hypotheses thus explained contrasting effects of heating on wheat yields under different Ta found in the field experiment as well as in many earlier studies. Well‐constrained tests of these hypotheses are vital for models used to project climate change impacts on agricultural ecosystems.

Clinically relevance of ectopic bone formation to the structure of TGF- β superfamily in stress condition

Formation of bone outside the skeletal system which can occur in all kinds of soft tissues is called Ectopic or Heterotopic Ossification (HO). It is the abnormal formation of true bone within extra skeletal soft tissues. The TGF-β super family several physiological processes are mediate by these polypeptides such as regulates bone formation and resorption as well as osteoclasts differentiation and survival is stimulated by them. Total of 21 head injured patients admitted in the hospital between 8 to 33 years old. All individuals are treated with indomethacin to control HO formation. The red light treatment and heat lamp exposure were done for 20 min in each day of physiotherapy. Both effective members of transforming growth factor- β, superfamily were analyzed by molecular mechanic methods in amber force field. Montecarlo simulation was done for 200 pSec and the ψ, φ angles of each amino acids were calculated. Clinically, of 25 potentially relevant records identified, 21 were related to HO. Following the treatment, 11 individuals showed the response to heat exposure and physical exercises. 9 out of 21 not only never do effective response to heat treatment, but also progress the HO formation. The results reveal that 2 tgi tends to arrange the protein critical angels of φ and ψ, into more favored and/ or allowed region and the formation and development of right handed, left handed α- helices and β- pleated sheath will be more facilitated because of rising in temperature. It is suggested that this phenomenon cause 2tgi to act in a better thermodynamic situation. Key words: Ramachandran plot, Montecarlo simulation ectopic bone formation, transforming growth factor- β; 1tfg; 2tgi.

Procedures for Rat &lt;em&gt;in situ&lt;/em&gt; Skeletal Muscle Contractile Properties

There are many circumstances where it is desirable to obtain the contractile response of skeletal muscle under physiological circumstances: normal circulation, intact whole muscle, at body temperature. This includes the study of contractile responses like posttetanic potentiation, staircase and fatigue. Furthermore, the consequences of disease, disuse, injury, training and drug treatment can be of interest. This video demonstrates appropriate procedures to set up and use this valuable muscle preparation.To set up this preparation, the animal must be anesthetized, and the medial gastrocnemius muscle is surgically isolated, with the origin intact. Care must be taken to maintain the blood and nerve supplies. A long section of the sciatic nerve is cleared of connective tissue, and severed proximally. All branches of the distal stump that do not innervate the medial gastrocnemius muscle are severed. The distal nerve stump is inserted into a cuff lined with stainless steel stimulating wires. The calcaneus is severed, leaving a small piece of bone still attached to the Achilles tendon. Sonometric crystals and/or electrodes for electromyography can be inserted. Immobilization by metal probes in the femur and tibia prevents movement of the muscle origin. The Achilles tendon is attached to the force transducer and the loosened skin is pulled up at the sides to form a container that is filled with warmed paraffin oil. The oil distributes heat evenly and minimizes evaporative heat loss. A heat lamp is directed on the muscle, and the muscle and rat are allowed to warm up to 37°C. While it is warming, maximal voltage and optimal length can be determined. These are important initial conditions for any experiment on intact whole muscle. The experiment may include determination of standard contractile properties, like the force-frequency relationship, force-length relationship, and force-velocity relationship.With care in surgical isolation, immobilization of the origin of the muscle and alignment of the muscle-tendon unit with the force transducer, and proper data analysis, high quality measurements can be obtained with this muscle preparation.

Procedures for Rat &lt;em&gt;in situ&lt;/em&gt; Skeletal Muscle Contractile Properties

There are many circumstances where it is desirable to obtain the contractile response of skeletal muscle under physiological circumstances: normal circulation, intact whole muscle, at body temperature. This includes the study of contractile responses like posttetanic potentiation, staircase and fatigue. Furthermore, the consequences of disease, disuse, injury, training and drug treatment can be of interest. This video demonstrates appropriate procedures to set up and use this valuable muscle preparation. To set up this preparation, the animal must be anesthetized, and the medial gastrocnemius muscle is surgically isolated, with the origin intact. Care must be taken to maintain the blood and nerve supplies. A long section of the sciatic nerve is cleared of connective tissue, and severed proximally. All branches of the distal stump that do not innervate the medial gastrocnemius muscle are severed. The distal nerve stump is inserted into a cuff lined with stainless steel stimulating wires. The calcaneus is severed, leaving a small piece of bone still attached to the Achilles tendon. Sonometric crystals and/or electrodes for electromyography can be inserted. Immobilization by metal probes in the femur and tibia prevents movement of the muscle origin. The Achilles tendon is attached to the force transducer and the loosened skin is pulled up at the sides to form a container that is filled with warmed paraffin oil. The oil distributes heat evenly and minimizes evaporative heat loss. A heat lamp is directed on the muscle, and the muscle and rat are allowed to warm up to 37°C. While it is warming, maximal voltage and optimal length can be determined. These are important initial conditions for any experiment on intact whole muscle. The experiment may include determination of standard contractile properties, like the force-frequency relationship, force-length relationship, and force-velocity relationship. With care in surgical isolation, immobilization of the origin of the muscle and alignment of the muscle-tendon unit with the force transducer, and proper data analysis, high quality measurements can be obtained with this muscle preparation.

A soil temperature control system for sapling study in alpine region

A soil temperature control system was designed for sapling study in alpine region and tested in summer, 2009. The system consisted of a power switch, voltage regulator, microcomputer timer, safety relays, temperature control device, temperature sensors, heating cables, fireproofing plastic pipes (PVC), 108 heavy-duty plastic containers and seedlings. The heating cables were held in six 2-layer PVC frames with 25 cm wide, 320 cm long and 25 cm high and three 1-layer frames with 25 cm wide and 320 cm long for 15A degrees C soil temperature treatment, half of the 2-layer frames were used for 20A degrees C and 25A degrees C soil temperature treatments, respectively. Each of the frames was installed at each of ditches with 30 cm wide, 330 cm long and 30 cm deep in size. 12 seedling containers with 20 cm top diameter, 18cm bottom diameter and 25 cm high were homogenously placed at each of the ditches, and spaces between the containers were filled with natural soil. The system was economic, and could increase soil temperatures obviously and uniformly, the maximal and minimal standard errors of soil temperatures were +/- 0.28 and +/- 0.05A degrees C at 10cm depth in the containers within each of all the ditches. In the system, aboveground environment was natural, diurnal and monthly soil temperatures varied with changing air temperature, the research results may be better to know the ecophysiological and growth responses of alpine saplings/seedlings to soil warming than that in greenhouse, laboratory, infrared heat lamp and open top chamber.

Faut-il encore utiliser la lampe chauffante en microchirurgie ?

The “heating lamp” is one of the complementary measures used to improve the survival rate of replantations and flaps. No publication demonstrated its efficiency, but burn injuries have been reported. The purpose of this study was to estimate the efficiency of the “heating lamp”. A questionnaire was sent to the members of the French society for surgery of the Hand, 16 % of who answered. The heat emitted by three electric bulbs (energy saving, strand, halogen) was measured at room temperature at 10, 15, 20 and 25 cm distance from the bulb over 4 h. The pressure of capillary drip PFC of the pulp of the index was measured in 10 healthy subjects by a laser Doppler. The PFC was measured without source of heat, then at 38, 40 and 42 °C, during 30 min. Among the answers to the questionnaire, 67 % never use the heating lamp. Among the 33 % who use it, the protocol was variable; 18 control the temperature without precision, 18 use it continuously, and 23 use it more than 24 hours. Nine reported complications, including eight burns (five flaps, three replantations). Subjectively, the majority of the users believe in its efficacy. Objectively, the heat emitted by the “heating lamp” was unimportant; whatever the distance from the source. The PFC did not vary with the temperature. The “heating lamp” is used empirically in microsurgery. The physical and physiological measures at the lower threshold for burns (43 °C) show that it is ineffective. Burns have been reported. In conclusion, the “heating lamp” should no longer be a part of the therapeutic arsenal of the hand surgeon.

Fabrication of Modified SWNTs/Glassy Carbon Electrode for the Determination of Dopamine

The SWNTs film was grown on the GC electrode by dropping a suspension of SWNTs in DMF on the GC electrode surface and then evaporating the solvent under an infrared heat lamp for 1 h, giving a modified SWNTs/GC electrode. Finally, the SWNTs/GC was rinsed thoroughly with absolute ethanol and deionized water just before use. The optimum working electrode, pH, and buffer solution were glassy carbon electrode (GC), 0.1 M phosphate buffer pH 7.5 respectively. The SWNTs/DMF film on the GC surface increased linearly with the amounts of SWNTs suspension over the range from 1 to 10 µL, and then increased slightly from 10 to 20 µL. SWNTs suspension of 10 µL was used for making the modified glassy carbon electrode. DPV technique was employed for the determination of dopamine. The drug samples containing dopamine obtained from Radvitee Hospital, Bangkok Thailand were tested as in the mentioned procedure.

Neural mechanism of activity spread in the cat motor cortex and its relation to the intrinsic connectivity

Motor cortical points are linked by intrinsic horizontal connections having a recurrent network topology. However, it is not known whether neural activity can propagate over the area covered by these intrinsic connections and whether there are spatial anisotropies of synaptic strength, as opposed to synaptic density. Moreover, the mechanisms by which activity spreads have yet to be determined. To address these issues, an 8 × 8 microelectrode array was inserted in the forelimb area of the cat motor cortex (MCx). The centre of the array had a laser etched hole ∼500 μm in diameter. A microiontophoretic pipette, with a tip diameter of 2-3 μm, containing bicuculline methiodide (BIC) was inserted in the hole and driven to a depth of 1200-1400 μm from the cortical surface. BIC was ejected for ∼2min from the tip of the micropipette with positive direct current ranging between 20 and 40 nA in different experiments. This produced spontaneous nearly periodic bursts (0.2-1.0 Hz) of multi-unit activity in a radius of about 400 μm from the tip of the micropipette. The bursts of neural activity spread at a velocity of 0.11-0.24 ms⁻¹ (mean=0.14 mm ms⁻¹, SD=0.05)with decreasing amplitude.The area activated was on average 7.22 mm² (SD=0.91 mm²), or ∼92% of the area covered by the recording array. The mode of propagation was determined to occur by progressive recruitment of cortical territory, driven by a central locus of activity of some 400 μm in radius. Thus, activity did not propagate as a wave. Transection of the connections between the thalamus and MCx did not significantly alter the propagation velocity or the size of the recruited area, demonstrating that the bursts spread along the routes of intrinsic cortical connectivity. These experiments demonstrate that neural activity initiated within a small motor cortical locus (≤ 400 μm in radius) can recruit a relatively large neighbourhood in which a variety of muscles acting at several forelimb joints are represented. These results support the hypothesis that the MCx controls the forelimb musculature in an integrated and anticipatory manner based on a recurrent network topology

Impacts of multiple extreme winter warming events on sub‐Arctic heathland: phenology, reproduction, growth, and CO2flux responses

AbstractExtreme weather events can have strong negative impacts on species survival and community structure when surpassing lethal thresholds. Extreme, short‐lived, winter warming events in the Arctic rapidly melt snow and expose ecosystems to unseasonably warm air (for instance, 2–10 °C for 2–14 days) but upon return to normal winter climate exposes the ecosystem to much colder temperatures due to the loss of insulating snow. Single events have been shown to reduce plant reproduction and increase shoot mortality, but impacts of multiple events are little understood as are the broader impacts on community structure, growth, carbon balance, and nutrient cycling. To address these issues, we simulated week‐long extreme winter warming events – using infrared heating lamps and soil warming cables – for 3 consecutive years in a sub‐Arctic heathland dominated by the dwarf shrubsEmpetrum hermaphroditum, Vaccinium vitis‐idaea(both evergreen) andVaccinium myrtillus(deciduous). During the growing seasons after the second and third winter event, spring bud burst was delayed by up to a week forE. hermaphroditumandV. myrtillus, and berry production reduced by 11–75% and 52–95% forE. hermaphroditumandV. myrtillus, respectively. Greater shoot mortality occurred inE. hermaphroditum(up to 52%),V. vitis‐idaea(51%), andV. myrtillus(80%). Root growth was reduced by more than 25% but soil nutrient availability remained unaffected. Gross primary productivity was reduced by more than 50% in the summer following the third simulation. Overall, the extent of damage was considerable, and critically plant responses were opposite in direction to the increased growth seen in long‐term summer warming simulations and the ‘greening’ seen for some arctic regions. Given the Arctic is warming more in winter than summer, and extreme events are predicted to become more frequent, this generates large uncertainty in our current understanding of arctic ecosystem responses to climate change.

Serendipitous intersections with Jack Vallentyne

Serendipitous intersections with Jack Vallentyne

Pharmacologically induced hypothermia with cannabinoid receptor agonist WIN55, 212-2 after cardiopulmonary resuscitation*

To investigate whether hypothermia could be induced pharmacologically after resuscitation with the cannabinoid CB1/CB2 receptor agonist in a rat model and its effects on outcomes of cardiopulmonary resuscitation. Prospective, randomized, placebo-controlled experimental study. University-affiliated animal research laboratory. Ten healthy male Sprague-Dawley rats. Ventricular fibrillation was induced and untreated for 6 mins. Defibrillation was attempted after 8 mins of cardiopulmonary resuscitation. Thirty minutes after resuscitation, animals were randomized to receive either WIN55, 212-2 (1.0 mg/kg/hr) or vehicle placebo (1.4 mL/kg/hr) for 6 hrs. Before infusion, the temperature was maintained at 37°C in all the animals with the help of a heating lamp. The same temperature environment was maintained for both groups after infusion. Hemodynamic measurements and cardiac output, ejection fraction, and myocardial performance index were measured at baseline and hourly for 6 hrs after resuscitation. Survival time up to 72 hrs was observed. Blood temperature decreased progressively after infusion of WIN55, 212-2 from 37°C to 34°C 4 hrs after resuscitation. There was no significant change in blood temperature after 6 hrs of placebo infusion of the same volume and same infusate temperature. Significantly better postresuscitation myocardial function and longer durations of survival were observed in WIN55, 212-2-treated animals. The selective cannabinoid agonist, WIN55, 212-2, produced a significant reduction in blood temperature and improved postresuscitation myocardial functions and survival after cardiopulmonary resuscitation. The study results may provide a further option for early and effective induction of therapeutic hypothermia in settings of cardiopulmonary resuscitation.