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1

Reproducing Black's experiments: freezing point depression and supercooling of water  

Microsoft Academic Search

We carried out two historical experiments referred to by Joseph Black, one on freezing mixtures of salted water with ice and another on freezing supercooled pure water by a small disturbance. The results confirm thermodynamical predictions for the depression of the freezing point of salted water and for the latent heat of freezing of supercooled water respectively, which came after

J. Güémez; C. Fiolhais; M. Fiolhais

2002-01-01

2

Study of freezing-point depression of selected food extracts  

SciTech Connect

The phenomenon of freezing-point depression that accompanies the solute concentration of selected food extracts was investigated to reveal the characteristics of solid-liquid phase equilibrium. The freezing curves of various food extracts did not exhibit ideal solution behavior in the higher concentration range. The experimental data were fitted to new freezing-point depression equations by the method of nonlinear least squares, and the results clearly indicated that the calculated freezing points at various concentrations were in good agreement with the experimental data. Furthermore, by using the determined parameters, the freezing ratio and the activation coefficient were derived.

Tanaka, Fumihiko [Kagoshima Univ. (Japan). Dept. of Agricultural Systems Engineering; Murata, Satoshi; Habara, Kazuhiro; Amaratunga, K.S.P. [Kyushu Univ., Fukuoka (Japan). Dept. of Agricultural Engineering

1996-12-31

3

The Freezing Point Depression Law in Physical Chemistry.  

ERIC Educational Resources Information Center

Suggests a change in physical chemistry courses to use a slightly more complicated but significantly more useful generalization of the simple freezing point depression law. Lists reasons for the change and presents the treatment of solid-liquid equilibria where solid-solution is allowed. Provides a mathematical treatment. (MVL)

Franzen, Hugo F.

1988-01-01

4

New expressions to describe solution nonideal osmotic pressure, freezing point depression, and vapor pressure.  

PubMed

New empirical expressions for osmotic pressure, freezing point depression, and vapor pressure are proposed based on the concepts of volume occupancy and (or) hydration force. These expressions are in general inverse relationships in comparison to the standard ideal expressions for the same properties. The slopes of the new equations are determined by the molecular weight of the solute and known constants. The accuracy and precision of the molecular weights calculated from the slope are identical and approximately 1% for the experiments reported here. The nonideality of all three colligative expressions is described by a dimensionless constant called the solute-solvent interaction parameter I. The results on sucrose have the same I = 0.26 for all three solution properties. The nonideality parameter I increased from 0.26 on sucrose to 1.7 on hemoglobin to successfully describe the well-known nonideal response of macromolecules. PMID:1299270

Fullerton, G D; Zimmerman, R J; Cantu, C; Cameron, I L

1992-12-01

5

Relationship of amino acid composition and molecular weight of antifreeze glycopeptides to non-colligative freezing point depression.  

PubMed

Many polar fishes synthesize a group of eight glycopeptides that exhibit a non-colligative lowering of the freezing point of water. These glycopeptides range in molecular weight between 2600 and 33 700. The largest glycopeptides [1-5] lower the freezing point more than the small ones on a weight basis and contain only two amino acids, alanine and threonine, with the disaccharide galactose-N-acetyl-galactosamine attached to threonine. The small glycopeptides, 6, 7, and 8, also lower the freezing point and contain proline, which periodically substitutes for alanine. Glycopeptides with similar antifreeze properties isolated from the saffron cod and the Atlantic tomcod contain an additional amino acid, arginine, which substitutes for threonine in glycopeptide 6. In this study we address the question of whether differences in amino acid composition or molecular weight between large and small glycopeptides are responsible for the reduced freezing point depressing capability of the low molecular weight glycopeptides. The results indicate that the degree of amino acid substitutions that occur in glycopeptides 6-8 do not have a significant effect on the unusual freezing point lowering and that the observed decrease in freezing point depression with smaller glycopeptides can be accounted for on the basis of molecular weight. PMID:7115772

Schrag, J D; O'Grady, S M; DeVries, A L

1982-08-01

6

Calculations of Freezing Point Depression, Boiling Point Elevation, Vapor Pressure and Enthalpies of Vaporization of Electrolyte Solutions by a Modified Three-Characteristic Parameter Correlation Model  

Microsoft Academic Search

A method was proposed for calculating the thermodynamic properties, freezing point depression, boiling point elevation, vapor\\u000a pressure and enthalpy of vaporization for single solute electrolyte solutions, including aqueous and nonaqueous solutions,\\u000a based on a modified three-characteristic-parameter correlation model. When compared with the corresponding literature values,\\u000a the calculated results show that this method gives a very good approximation, especially for 1-1

Xinlei Ge; Xidong Wang

2009-01-01

7

Preliminary report on fluid inclusions from halites in the Castile and lower Salado formations of the Delaware Basin, southeastern New Mexico. [Freezing-point depression  

SciTech Connect

A suite of samples composed primarily of halite from the upper Castile and lower Salado Formations of the Permian Basin was selected from Waste Isolation Pilot Plant (WIPP) core for a reconnaissance study of fluid inclusions. Volume percent of these trapped fluids averaged 0.7% to 1%. Freezing-point depressions varied widely and appeared to be unrelated to fluid-inclusion type, to sedimentary facies, or to stratigraphic depth. However, because very low freezing points were usually associated with anhydrite, a relation may exist between freezing-point data and lithology. Dissolved sulfate values were constant through the Castile, then decreased markedly with lesser depth in the lower Salado. This trend correlates very well with observed mineralogy and is consistent with an interpretation of the occurrence of secondary polyhalite as a result of gypsum or anhydrite alteration with simultaneous consumption of dissolved sulfate from the coexisting fluids. Together with the abundance and distribution of fluid inclusions in primary or ''hopper'' crystal structures, this evidence suggests that inclusions seen in these halites did not migrate any significant geographical distance since their formation. 28 refs., 17 figs., 2 tabs.

Stein, C.L.

1985-09-01

8

Solutions : FreezePtDepression (20 Variations)  

NSDL National Science Digital Library

It takes 6.86 kg of ethylene glycol (antifreeze) to decrease the freezing point of 6.50 kg of water to -25.0 o F (-31.7 o C). How much sodium chloride (NaCl) would it take to decrease the freezing point of 6.50 kg of water to -25.0 o F? (Assuming all the salt will dissolve in that amount of water.)

9

7.NS Comparing Freezing Points  

NSDL National Science Digital Library

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: Ocean water freezes at about $-2 \\frac12 ^\\circ C$. Fresh water freezes at $0 ^\\circ C$. Antifreeze, a liquid used in the radiators of cars, freezes at...

10

Freezing Point of Milk: A Natural Way to Understand Colligative Properties  

ERIC Educational Resources Information Center

A laboratory experiment is presented in which the freezing point depression is analyzed using milk as solution. The nature of milk as a mixture of different solutes makes it a suitable probe to learn about colligative properties. The first part of the experiment illustrates the analytical use of freezing point measurements to control milk quality,…

Novo, Mercedes; Reija, Belen; Al-Soufi, Wajih

2007-01-01

11

Device and method for determining freezing points  

NASA Technical Reports Server (NTRS)

A freezing point method and device (10) are disclosed. The method and device pertain to an inflection point technique for determining the freezing points of mixtures. In both the method and device (10), the mixture is cooled to a point below its anticipated freezing point and then warmed at a substantially linear rate. During the warming process, the rate of increase of temperature of the mixture is monitored by, for example, thermocouple (28) with the thermocouple output signal being amplified and differentiated by a differentiator (42). The rate of increase of temperature data are analyzed and a peak rate of increase of temperature is identified. In the preferred device (10) a computer (22) is utilized to analyze the rate of increase of temperature data following the warming process. Once the maximum rate of increase of temperature is identified, the corresponding temperature of the mixture is located and earmarked as being substantially equal to the freezing point of the mixture. In a preferred device (10), the computer (22), in addition to collecting the temperature and rate of change of temperature data, controls a programmable power supply (14) to provide a predetermined amount of cooling and warming current to thermoelectric modules (56).

Mathiprakasam, Balakrishnan (Inventor)

1986-01-01

12

High-freezing-point fuels used for aviation turbine engines  

NASA Technical Reports Server (NTRS)

Broadened-specification aviation fuels could be produced from a greater fraction of crude source material with improvements in fuel supply and price. These fuels, particularly those with increased final boiling temperatures, would have higher freezing temperatures than current aviation turbine fuels. The higher-freezing-point fuels can be substituted in the majority of present commercial flights, since temperature data indicate that in-flight fuel temperatures are relatively mild. For the small but significant fraction of commercial flights where low fuel temperatures make higher freezing-point fuel use unacceptable, adaptations to the fuel or fuel system may be made to accommodate this fuel. Several techniques are discussed. Fuel heating is the most promising concept. One simple system design uses existing heat rejection from the fuel-lubricating oil cooler, another uses an engine-driven generator for electrical heating. Both systems offer advantages that outweigh the obvious penalties.

Friedman, R.

1979-01-01

13

High freezing point fuels used for aviation turbine engines  

NASA Technical Reports Server (NTRS)

Broadened-specification aviation fuels could be produced from a greater fraction of crude source material with improvements in fuel supply and price. These fuels, particularly those with increased final boiling temperatures, would have higher freezing temperatures than current aviation turbine fuels. For the small but significant fraction of commercial flights where low fuel temperatures make higher freezing-point fuel use unacceptable, adaptations to the fuel or fuel system may be made to accommodate this fuel. Several techniques are discussed. Fuel heating is the most promising concept. One simple design uses existing heat rejection from the fuel-lubricating oil cooler, another uses an engine-driven generator for electrical heating.

Friedman, R.

1979-01-01

14

Freezing and Melting  

NSDL National Science Digital Library

This article tells how the freezing point of a substance is also its melting point. The energy of the substance's molecules changes with temperature, thus with changes in state. Also described is how freezing points can be lowered, or depressed, by adding a substance.

2010-01-01

15

Freezing Points of Bulking Agents Used in Manufacture of Low-Calorie Frozen Desserts1  

Microsoft Academic Search

Freezing points of solutions of poly- dextrose, polydextrose partially neu- tralized with potassium hydroxide, sor- bitol, and microcrystalline cellulose at concentrations commonly used in frozen desserts were compared with those of similar concentrations of sucrose. Solu- tions of polydextrose and polydextrose partially neutralized with potassium hy- droxide exhibited higher freezing points. Freezing points of sorbitol solutions were lower and microcrystalline

Robert J. Baer; Kirk A. Baldwin

1984-01-01

16

Open Zinc Freezing-Point Cell Assembly and Evaluation  

NASA Astrophysics Data System (ADS)

An open metal freezing-point cell design has been developed in the Laboratory of Metrology and Quality. According to our design, a zinc cell was successfully assembled. The paper presents the needed parts for the cell, the cleaning process, and sealing of the cell. The assembled cell was then evaluated by comparison with two commercial closed zinc cells of different manufacturers. The freezing plateaus of the cells were measured, and a direct cell comparison was made. It was shown that the assembled open cell performed better than the used closed cell and was close to the brand new closed cell. The nominal purity of the zinc used for the open cell was 7 N, but the freezing plateau measurement suggests a higher impurity concentration. It was assumed that the zinc was contaminated to some extent during the process of cutting as its original shape was an irregular cylinder. The uncertainty due to impurities for the assembled cell is estimated to be 0.3 mK. Furthermore, the immersion profile and the pressure coefficient were measured. Both results are close to their theoretical values.

Žužek, V.; Batagelj, V.; Drnovšek, J.; Bojkovski, J.

2014-07-01

17

Estimation of Freezing Point of Hydrocarbon and Hydrofluorocarbon Mixtures for Mixed Refrigerant jt Cryocooler  

NASA Astrophysics Data System (ADS)

Estimating the freezing point of refrigerant is an essential part in designing an MR JT (Mixed refrigerant Joule-Thomson) cryocooler to prevent itself from clogging and to operate with stability. There were researches on estimating freezing point, but some of them resulted in the wrong prediction of clogging. In this paper, the freezing point of the MR is precisely estimated with caution of clogging. The solubility of HC (hydrocarbon) and HFC (hydrofluorocarbon) mixture components are obtained with their activity coefficients, which represent the molecular interaction among the components. The freezing points of the MR JT cryocooler are systematically investigated in the operating temperature range from 70 K to 90 K.

Hwang, G.; Lee, J.; Jeong, S.

2010-04-01

18

Practical limitations of ITS-90 from the mercury triple point to the silver freeze point  

SciTech Connect

The NPL published a forward to the ITS-90 text as follows:- 'The purpose of the ITS is to define procedures by which certain specified practical thermometers of the required quality can be calibrated in such a way that the values of temperature obtained from them can be precise and reproducible, while at the same time closely approximating the corresponding thermodynamic values.' [1]. The paper investigates the properties of thirty four lots of 6N pure metal used to make cells conforming to ITS-90 from mercury through silver over a period of twenty years. Three hundred individual cells are analysed by the impurities listed and supplied with each lot, melt and freeze curve slopes are also summarised for each lot and depressions calculated. These are then compared to the slopes and depressions suggested in the Supplementary Information for the ITS-90 and in CCT/2000-13 'Optimal Realizations'. Results are summarised, tabulated and discussed. Three lots of the thirty four were found to produce cells outside 6N expectations; however the remaining thirty one lots no matter how well or badly the accompanying certification was presented produced cells that conformed to 6N expectations as suggested in Supplementary Information to ITS-90 and CCT/2000-13.

Tavener, J. P.; Tavener, S. J.; Tavener, I. F.; Davies, N. [Isothermal Technology Ltd (Isotech), Pine Grove, Southport, Merseyside, PR9 9AG, England (United Kingdom)] [Isothermal Technology Ltd (Isotech), Pine Grove, Southport, Merseyside, PR9 9AG, England (United Kingdom)

2013-09-11

19

Design and evaluation of aircraft heat source systems for use with high-freezing point fuels  

NASA Technical Reports Server (NTRS)

The objectives were the design, performance and economic analyses of practical aircraft fuel heating systems that would permit the use of high freezing-point fuels on long-range aircraft. Two hypothetical hydrocarbon fuels with freezing points of -29 C and -18 C were used to represent the variation from current day jet fuels. A Boeing 747-200 with JT9D-7/7A engines was used as the baseline aircraft. A 9300 Km mission was used as the mission length from which the heat requirements to maintain the fuel above its freezing point was based.

Pasion, A. J.

1979-01-01

20

An Equipment to Measure the Freezing Point of Soils under Higher Pressure  

NASA Astrophysics Data System (ADS)

Soil freezing point is the highest temperature at which ice can be presented in the system and soil can be referred to as frozen. The freezing temperature of soil is an important parameter for solving many practical problems in civil engineering, such as evaluation of soil freezing depth, prediction of soil heaving, force of soil suction, etc. However, as the freezing temperature is always affected by many factors like soil particle size, mineral composition, water content and the external pressure endured by soils, to measure soil freezing point is a rather difficult task until now, not to mention the soil suffering higher pressure. But recently, with the artificial freezing technology widely used in the excavation of deep underground space, the frozen wall thickness is a key factor to impact the security and stability of deep frozen wall. To determine the freeze wall thickness, the location of the freezing front must be determined firstly, which will deal with the determination of the soil freezing temperature. So how to measure the freezing temperature of soil suffering higher pressure is an important problem to be solved. This paper will introduce an equipment which was developed lately by State Key Laboratory of Frozen Soil Engineering to measure the freezing-point of soils under higher pressure. The equipment is consisted of cooling and keeping temperature system, temperature sensor and data collection system. By cooling and keeping temperature system, not only can we make the higher pressure soil sample's temperature drop to a discretionary minus temperature, but also keep it and reduce the heat exchange of soil sample with the outside. The temperature sensor is the key part to our measurement, which is featured by high precision and high sensitivity, what is more important is that the temperature sensor can work in a higher pressure condition. Moreover, the major benefit of this equipment is that the soil specimen's loads can be loaded by any microcomputer control electron universal testing machines. All of above mentioned advantages of this equipment ensures one to catch up the moment soil turns from the thawed state into ice and enable one to determine the freezing point experimentally by recording the temperature-time history (cooling curve) at particular points within the sample used for analysis. Therefore, this equipment has excellent characteristics such as compact construction, convenient operation, high reliability and the measuring accuracy. The authors would like to thank the following agents for their financial supports: the National Natural Science Foundation (No.41071048),Hundred Talent Young Scientists program of the Chinese Academy of Sciences granted to Dr. Zhi Wen.

Wang, Dayan; Guan, Hui; Wen, Zhi; Ma, Wei

2014-05-01

21

Evaluation of methods for rapid determination of freezing point of aviation fuels  

NASA Technical Reports Server (NTRS)

Methods for identification of the more promising concepts for the development of a portable instrument to rapidly determine the freezing point of aviation fuels are described. The evaluation process consisted of: (1) collection of information on techniques previously used for the determination of the freezing point, (2) screening and selection of these techniques for further evaluation of their suitability in a portable unit for rapid measurement, and (3) an extensive experimental evaluation of the selected techniques and a final selection of the most promising technique. Test apparatuses employing differential thermal analysis and the change in optical transparency during phase change were evaluated and tested. A technique similar to differential thermal analysis using no reference fuel was investigated. In this method, the freezing point was obtained by digitizing the data and locating the point of inflection. Results obtained using this technique compare well with those obtained elsewhere using different techniques. A conceptual design of a portable instrument incorporating this technique is presented.

Mathiprakasam, B.

1982-01-01

22

Realization of the Temperature Scale in the Range from 234.3 K (Hg Triple Point) to 1084.62°C (Cu Freezing Point) in Croatia  

NASA Astrophysics Data System (ADS)

This article describes the realization of the International Temperature Scale in the range from 234.3 K (mercury triple point) to 1084.62°C (copper freezing point) at the Laboratory for Process Measurement (LPM), Faculty of Mechanical Engineering and Naval Architecture (FSB), University of Zagreb. The system for the realization of the ITS-90 consists of the sealed fixed-point cells (mercury triple point, water triple point and gallium melting point) and the apparatus designed for the optimal realization of open fixed-point cells which include the gallium melting point, tin freezing point, zinc freezing point, aluminum freezing point, and copper freezing point. The maintenance of the open fixed-point cells is described, including the system for filling the cells with pure argon and for maintaining the pressure during the realization.

Zvizdic, Davor; Veliki, Tomislav; Grgec Bermanec, Lovorka

2008-06-01

23

Nano materials for efficiently lowering the freezing point of heat transfer nanofluids  

NASA Astrophysics Data System (ADS)

In this paper, we report, for the first time, the effect of the lowered freezing point in a 50% water / 50% antifreeze coolant (PAC) or 50% water / 50% ethylene glycol (EG) solution by the addition of carbon nanotubes and other particles. The experimental results indicated that the nano materials are much more efficient (hundreds fold) in lowering the freezing point than the regular ionic materials (e.g. NaCl). The possible explanation for this interesting phenomenon is the colligative property of fluid and relative small size of nano material. It is quite certain that the carbon nanotubes and metal oxide nano particles could be a wonderful candidate for the nano coolant application because they could not only increase the thermal conductivity, but also efficiently lower the freezing point of traditional coolants.

Hong, Haiping; Roy, Walter

2007-09-01

24

Experimental results for the rapid determination of the freezing point of fuels  

NASA Technical Reports Server (NTRS)

Two methods for the rapid determination of the freezing point of fuels were investigated: an optical method, which detected the change in light transmission from the disappearance of solid particles in the melted fuel; and a differential thermal analysis (DTA) method, which sensed the latent heat of fusion. A laboratory apparatus was fabricated to test the two methods. Cooling was done by thermoelectric modules using an ice-water bath as a heat sink. The DTA method was later modified to eliminate the reference fuel. The data from the sample were digitized and a point of inflection, which corresponds to the ASTM D-2386 freezing point (final melting point), was identified from the derivative. The apparatus was modifified to cool the fuel to -60 C and controls were added for maintaining constant cooling rate, rewarming rate, and hold time at minimum temperature. A parametric series of tests were run for twelve fuels with freezing points from -10 C to -50 C, varying cooling rate, rewarming rate, and hold time. Based on the results, an optimum test procedure was established. The results showed good agreement with ASTM D-2386 freezing point and differential scanning calorimetry results.

Mathiprakasam, B.

1984-01-01

25

A Four-Zone Furnace for Realization of Silver and Gold Freezing Points  

NASA Astrophysics Data System (ADS)

Recently, the Thermocouple Calibration Laboratory at the National Institute of Standards and Technology has used sodium heat-pipe furnaces for the realization of ITS-90 freezing points of aluminum, silver, and gold. When using a fixed-point cell mounted in a long silica-glass tube that extends to ambient temperature at the top of the furnace, we have observed significant thermal gradients along the well of the fixed-point cell, with the top of the well up to 0.1 K colder than the bottom. Furthermore, the heat-pipe lifetime is limited when used at the gold point (1064.18 °C) for more than a few hundred hours. To address these problems, we have designed and built a four-zone furnace based on a temperature-controlled, graphite isothermal block, suspended inside a three-zone tube furnace. The three-zone furnace is of a commercial design. The graphite block is enclosed in an alloy 600 (Inconel) can, allowing the graphite to be maintained in an argon atmosphere. The argon pressure is maintained at one atmosphere at all temperatures, thereby greatly reducing the stress on the can. Heaters in intimate contact with the can allow temperature control of the fourth inner zone to high accuracy. In this paper, the measured thermal stability and uniformity achieved with this furnace are presented. We also give results of test freezes of a silver freezing-point cell.

Ripple, D. C.; Garrity, K. M.; Meyer, C. W.

2003-09-01

26

Depression of melting point for protective aluminum oxide films  

NASA Astrophysics Data System (ADS)

The protective aluminum oxide film naturally formed on a surface of aluminum has a thickness in the range of 3-5 nm. Its melting causes loss of its continuity, which may significantly affect the ignition and combustion processes and their relative time scales. Melting of the alumina film also plays an important role when aluminum powders are used to prepare composites and/or being sintered. This letter quantifies depression of the melting point of an alumina film based on its nano-meter thickness. A theoretical estimate is supported by experiments relying on a detected change in the optical properties of naturally oxidized aluminum particles heated in an inert environment.

Dreizin, E. L.; Allen, D. J.; Glumac, N. G.

2015-01-01

27

Prospective Chemistry Teachers' Misconceptions about Colligative Properties: Boiling Point Elevation and Freezing Point Depression  

ERIC Educational Resources Information Center

This study aimed at identifying prospective chemistry teachers' misconceptions of colligative properties. In order to fulfill this aim, a diagnostic test composed of four open-ended questions was used. The test was administered to seventy-eight prospective chemistry teachers just before qualifying to teaching in secondary schools. Nine different…

Pinarbasi, Tacettin; Sozbilir, Mustafa; Canpolat, Nurtac

2009-01-01

28

Improvements in the realization of the ITS-90 over the temperature range from the melting point of gallium to the freezing point of silver at NIM  

SciTech Connect

The temperature primary standard over the range from the melting point of gallium to the freezing point of silver in National institute of Metrology (NIM), China, was established in the early 1990s. The performance of all of fixed-point furnaces degraded and needs to be updated due to many years of use. Nowadays, the satisfactory fixed point materials can be available with the development of the modern purification techniques. NIM plans to use a group of three cells for each defining fixed point temperature. In this way the eventual drift of individual cells can be evidenced by periodic intercomparison and this will increase the reliability in disseminating the ITS-90 in China. This article describes the recent improvements in realization of ITS-90 over temperature range from the melting point of gallium to the freezing point of silver at NIM. Taking advantages of the technological advances in the design and manufacture of furnaces, the new three-zone furnaces and the open-type fixed points were developed from the freezing point of indium to the freezing point of silver, and a furnace with the three-zone semiconductor cooling was designed to automatically realize the melting point of gallium. The reproducibility of the new melting point of gallium and the new open-type freezing points of In, Sn, Zn. Al and Ag is improved, especially the freezing points of Al and Ag with the reproducibility of 0.2mK and 0.5mK respectively. The expanded uncertainty in the realization of these defining fixed point temperatures is 0.34mK, 0.44mK, 0.54mK, 0.60mK, 1.30mK and 1.88mK respectively.

Sun, J.; Zhang, J. T.; Ping, Q. [National institute of Metrology, Beijing (China)] [National institute of Metrology, Beijing (China)

2013-09-11

29

When hot water freezes before cold  

E-print Network

I suggest that the origin of the Mpemba effect (the freezing of hot water before cold) is freezing-point depression by solutes, either gaseous or solid, whose solubility decreases with increasing temperature so that they are removed when water is heated. They are concentrated ahead of the freezing front by zone refining in water that has not been heated, reduce the temperature of the freezing front, and thereby reduce the temperature gradient and heat flux, slowing the progress of the front. I present a simple calculation of this effect, and suggest experiments to test this hypothesis.

J. I. Katz

2006-04-27

30

Study on the melting and freezing behaviour of high temperature binary eutectic fixed points using differential scanning calorimetry  

NASA Astrophysics Data System (ADS)

We have measured the heat flux accompanying the melting or freezing of metal (or metalloid)-carbon eutectics, using differential scanning calorimetry (DSC) to identify appropriate binary systems for secondary thermometry fixed points. Well-known alloy systems such as Fe-C and Ni-C showed reproducible endothermic and exothermic peaks that represent melting and freezing reactions in the DSC measurement. Furthermore, a new Si-C system with a eutectic composition showed reproducible melting and freezing peaks in the DSC measurements. Based on the results by DSC, we identified the Si-SiC eutectic point as a possible eutectic fixed point. To confirm this possibility, we made a Si-SiC cell for thermocouple thermometry and measured its melting and freezing characteristics using a Pt/Pd thermocouple. The melting temperature of the Si-SiC eutectic was reproducible to within 0.02 °C (one standard deviation). From the results, we found that Si-SiC has possibility as a new eutectic fixed point at temperatures around 1400 °C. We also concluded that DSC analysis could be used to measure the reproducibility of freezing and melting reactions that are to be used as fixed points for thermometry, because it is a rapid and easy-to-use tool for characterizing the thermal behaviour of materials with only a small sample.

Kwon, Su Yong; Kim, Yong-Gyoo; Yang, Inseok

2010-06-01

31

The initial freezing point temperature of beef rises with the rise in pH: a short communication.  

PubMed

This study tested the hypothesis that the initial freezing point temperature of meat is affected by pH. Sixty four bovine M. longissimus thoracis et lumborum were classified into two ultimate pH groups: low (<5.8) and high pH (>6.2) and their cooling and freezing point temperatures were determined. The initial freezing temperatures for beef ranged from -0.9 to -1.5°C (?=0.6°C) with the higher and lower temperatures associated with high and low ultimate pH respectively. There was a significant correlation (r=+0.73, P<0.01) between beef pH and freezing point temperature in the present study. The outcome of this study has implications for the meat industry where evidence of freezing (ice formation) in a shipment as a result of high pH meat could result in a container load of valuable chilled product being downgraded to a lower value frozen product. PMID:23410892

Farouk, M M; Kemp, R M; Cartwright, S; North, M

2013-05-01

32

Depression  

MedlinePLUS

... major depressive episode within one month after delivery. Seasonal affective disorder (SAD), which is a depression during the winter months, when there is less natural sunlight. Return to top What causes depression? There is no single cause of depression. ...

33

Depression  

MedlinePLUS

... children, teens, and seniors. Causes & Risk Factors What causes depression? Depression may be caused by an imbalance of ... such as heart disease, diabetes, or cancer may cause depression. Events in your life. Depression can be triggered ...

34

Working and Non-Working University Students: Anxiety, Depression, and Grade Point Average  

ERIC Educational Resources Information Center

This study explored the differences between 110 working and non-working students in terms of mental health, academic achievement, and perceptions about student employment. Anxiety and depression were measured by the Beck Anxiety Inventory and the Beck Depression Inventory-II. Academic achievement was measured by grade point average. Perceptions of…

Mounsey, Rebecca; Vandehey, Michael A.; Diekhoff, George M.

2013-01-01

35

Serum Protein and Casein Concentration: Effect on pH and Freezing Point of Milk with Added CO21  

Microsoft Academic Search

The objective of this studywas to determine the effect of protein concentration and protein type (i.e., casein (CN) and serum protein (SP)) on pH (0°C) and freezing point (FP) of skim milk upon CO2 injection at 0°C. CN- free skim milks with increasing SP content (0, 3, and 6%) and skim milks with the same SP content (0.6%) but increasing

Y. Ma; D. M. Barbano

2003-01-01

36

Depression  

MedlinePLUS

... People Get Depressed? Cutting Talking to Parents About Depression Stress & Coping Center Seasonal Affective Disorder Finding Low-Cost Mental Health Care 5 Ways to Fight Depression Posttraumatic Stress Disorder Contact Us Print Additional resources ...

37

Depression  

MedlinePLUS

... sadness and the disabling weight of clinical depression. Causes Depression can affect anyone—even a person who appears ... g., a brain tumor or vitamin deficiency) can cause depression, so it is important to be evaluated by ...

38

[Depression.  

PubMed

The prevalence of depression is not clearly established, but estimated to 3-4% in a Danish questionnaire study. Lifetime's prevalences of 12-17% are reported in other community samples. In the current diagnostic system depression is defined categorically and operationally. It has been argued, that these diagnostic criteria represent an oversimplification, which has blurred the concept of depression. We suggest a greater emphasis on the depressed mood as the core symptom of depression, which may increase the specificity of the diagnosis. Furthermore, basic principles for the treatment of depression are presented. PMID:25292467

Kessing, Lars Veddel; Bukh, Jens Drachmann

2014-08-01

39

Depression  

MedlinePLUS

... is most likely due to a lack of sunlight. Depression may also alternate with mania (known as ... therapy using a special lamp that is like sunlight. If you have moderate to severe depression, the ...

40

Size-dependent melting point depression of nanostructures: Nanocalorimetric measurements  

Microsoft Academic Search

The melting behavior of 0.1-10-nm-thick discontinuous indium films formed by evaporation on amorphous silicon nitride is investigated by an ultrasensitive thin-film scanning calorimetry technique. The films consist of ensembles of nanostructures for which the size dependence of the melting temperature and latent heat of fusion are determined. The relationship between the nanostructure radius and the corresponding melting point and latent

M. Zhang; M. Yu. Efremov; F. Schiettekatte; E. A. Olson; A. T. Kwan; S. L. Lai; T. Wisleder; J. E. Greene; L. H. Allen

2000-01-01

41

Depression of melting point of multidomained bismuth in aluminum based metallic glass nanocomposites  

Microsoft Academic Search

We report the synthesis of nanocomposites of Bi in an aluminum based metallic glass matrix by rapid solidification. It is shown that constrained melting and solidification of nanometer sized embedded Bi particles lead to the formation of symmetry related multidomained particles. The Bi particles exhibit a significantly large depression of bulk melting point (over 100 K) requiring a free energy

R. Goswami; K. Chattopadhyay

1996-01-01

42

Theoretical Analysis of Melting Point Depression of Pure Metals in Different Initial Configurations  

NASA Astrophysics Data System (ADS)

A general equation is derived for melting point depression (MPD) of pure metals, consisting of three terms: MPD due to high gas pressure, MPD due to high strain energy, and MPD due to small size of the metal. Particular equations are derived for different configurations of the solid metal, including grains embedded within a matrix. The equations obtained in this paper can be used to design nano-joining structures with improved MPD.

Kaptay, G.; Janczak-Rusch, J.; Pigozzi, G.; Jeurgens, L. P. H.

2014-05-01

43

Negative pressures and melting point depression in oxide-coated liquid metal droplets  

NASA Technical Reports Server (NTRS)

Negative pressures and melting point depression in oxide-coated liquid metal droplets are studied. The calculation presented show the existence of large negative pressures when the oxide coating is thick enough. The change in the melting point caused by these negative pressures should be considered in studies of homogeneous crystal nucleation. Furthermore, since the negative pressure raises the entropy of the melt, it increases the entropy loss at the crystal-melt interface; the resulting increase of the surface tension could have a large effect on the homogeneous nucleation frequency.

Spaepen, F.; Turnbull, D.

1979-01-01

44

The influence of ionizable and non-ionizable compounds in milk upon its freezing point  

E-print Network

LIBRARY A d M COLLEGE OF TEXAS TES ISPLUSSCg OP IOSISJSLS kg9 SOS~IOSISLSLS COlQ'CURES Ig MILK UPOS ITS Pggggigg TOIST k Thesis Praak Piakortea Subaittod to tho Graduate Sohool of the dgrioultural aad Meohsaical College of Tosas in partial... ooatoat bye Chafrnan ot Cossatttoe Eoal of Dopartaont or Stukont visor lngust 195$ TiBLR OP COSTXXTS Page IXTRODUCT I OX . . RXVIXW Oy LITXRLTURX. XXPXRIMXRTdL PROCXDUBX. RXSUI TS, Tho Iaflueaoe of Mastitis oa the pressing Point of Milk, Per...

Pinkerton, Frank

1955-01-01

45

Depressants  

MedlinePLUS

... can slow heart rate and breathing enough to cause death. Legal status in the United States Most depressants are controlled substances that range from Schedule I to Schedule IV under the Controlled Substances Act, depending on their risk for abuse and whether they currently have an accepted medical ...

46

Activity coefficients and free energies of nonionic mixed surfactant solutions from vapor-pressure and freezing-point osmometry.  

PubMed

The thermodynamic properties of mixed surfactant solutions are widely investigated, prompted by numerous practical applications of these systems and by interest in molecular association and self-organization. General techniques for measuring thermodynamic activities, such as isopiestic equilibration, are well-established for multicomponent solutions. Surprisingly, these techniques have not yet been applied to mixed surfactant solutions, despite the importance of the free energy for micelle stability. In this study, equations are developed for the osmotic coefficients of solutions of nonionic surfactant A + nonionic surfactant B. A mass-action model is used, with virial equations for the activity coefficients of the micelles and free surfactant monomer species. The equations are fitted to osmotic coefficients of aqueous decylsulfobetaine + dodecylsulfobetaine solutions measured by vapor-pressure and freezing-point osmometry. Equilibrium constants for mixed-micelle formation are calculated from the free monomer concentrations at the critical micelle concentrations. The derived activity coefficients of the micelles and free monomers indicate large departures from ideal solution behavior, even for dilute solutions of the surfactants. Stoichiometric activity coefficients of the total surfactant components are evaluated by Gibbs-Duhem integration of the osmotic coefficients. Relatively simple colligative property measurements hold considerable promise for free energy studies of multicomponent surfactant solutions. PMID:21504169

MacNeil, Jennifer A; Ray, Gargi Basu; Leaist, Derek G

2011-05-19

47

Ice nucleation in solutions and freeze-avoiding insects-homogeneous or heterogeneous?  

PubMed

This article challenges the common view that solutions and cold-hardy freeze-avoiding insects always freeze by heterogeneous nucleation. Data are presented to show that the nucleation temperatures of a variety of solutions and freeze-avoiding insects are a function of the water volume as described by the data previously published by Bigg in 1953. The article also points out that the relationships between melting point depression and depression of nucleation temperature are different for samples undergoing homogeneous nucleation and those undergoing heterogeneous nucleation. Aqueous solutions and freeze-avoiding insects display a relationship like that of homogeneously nucleated samples. It is also argued that the identity of the "impurities" assumed to cause heterogeneous nucleation in aqueous solutions and insects is obscure and that the "impurities" have features which make their existence rather unlikely. PMID:15157779

Zachariassen, Karl Erik; Kristiansen, Erlend; Pedersen, Sindre Andre; Hammel, Harold T

2004-06-01

48

Freezing in confined geometries  

NASA Technical Reports Server (NTRS)

Results of detailed structural studies, using elastic neutron scattering, of the freezing of liquid O2 and D2 in porous vycor glass, are presented. The experimental studies have been complemented by computer simulations of the dynamics of freezing of a Lennard-Jones liquid in narrow channels bounded by molecular walls. Results point to a new simple physical interpretation of freezing in confined geometries.

Sokol, P. E.; Ma, W. J.; Herwig, K. W.; Snow, W. M.; Wang, Y.; Koplik, Joel; Banavar, Jayanth R.

1992-01-01

49

Freezing Fish and Shellfish.  

E-print Network

means of preserving the fresh-caught quality of fish and shellfish. Why Freeze? Freezing preserves foods by lowering their tem peratures to a point not conducive to bacterial growth and natural enzyme action. Many spoilage bacteria are destroyed... by freezing, and those that survive are unable to grow at the low temperature. A fresh seafood product can spoil when bacteria are not present. Natural enzymes that help fish digest food and carry on natural metabolism in the cells of the fish...

Nickelson, Ranzell; Reddell, Annette

1980-01-01

50

A new optimal control model for reproducing two-point reaching movements of human three-joint arm with wrist joint's freezing mechanism  

Microsoft Academic Search

A new optimal control model of human arms has been developed to simulate two-point reaching movement characteristics for human three-joint arms (shoulder, elbow, and wrist joints) and its fundamental performance has been clarified. The new model is formulated by extending the previous two-joint modified minimum torque-change model to a three-joint model with a freezing mechanism in its wrist joint and

Toshikazu Matsui

2009-01-01

51

Melting Point Depression and Kinetic Effects of Cooling on Crystallization in Poly(vinylidene fluoride)Poly(methyl methacrylate) Mixtures  

Microsoft Academic Search

Thermal analysis of solution cast mixtures of poly(viny1idene fluoride) (PVF2) and poly(methy1 methacrylate) (PMMA) has been carried out with various programmed temperature profiles. Results from experi- ments conducted in a quasi-equilibrium state show that PVF:! crystallizes in the mixture upon cooling. Further- more, depressions were observed in the melting and the crystallization temperatures. The melting point depression phenomenon is found

T. Nishi; T. T. Wang

1975-01-01

52

The effect of nanohybrid materials on the pour-point and viscosity depressing of waxy crude oil  

Microsoft Academic Search

The pipeline transportation of waxy crude oil is a problem both at home and abroad. In this paper, a novel nanohybrid pour-point\\u000a depressant (PPD) was used to decrease the pour point and viscosity of waxy crude oil. The pour point and apparent viscosity\\u000a of waxy crude oil was decreased significantly upon addition of the nanohybrid PPD, and the long-term stability

Feng Wang; DongMin Zhang; YanFen Ding; LiXin Zhang; MingShu Yang; BaoLiang Jiang; ShiMin Zhang; MuYang Ai; GuangWen Liu; ShuJie Zhi; LianFeng Huo; Xin Ouyang; Li Li

2011-01-01

53

Influence of freezing temperatures on a cactus, Coryphantha vivipara  

Microsoft Academic Search

Coryphantha vivipara (Nutt.) Britton & Rose var. deserti (Engelm.) W.T. Marshall (Cactaceae) survived snow and tissue temperatures of-12°C in southern Nevada. However, the freezing point depression of the cell sap was only about 0.9°C. When the nocturnal air temperature in the laboratory was reduced from 10°C to-10°C for one night, the optimum temperature for CO2 uptake shifted from 10°C to

Park S. Nobel

1981-01-01

54

Experimental and analytical investigation of a freezing point depressant fluid ice protection system. M.S. Thesis. Final Report  

NASA Technical Reports Server (NTRS)

A glycol-exuding porous leading edge ice protection system was tested in the NASA Icing Research Tunnel. Stainless steel mesh, laser drilled titanium, and composite panels were tested on two general aviation wing sections. Two different glycol-water solutions were evaluated. Minimum glycol flow rates required for anti-icing were obtained as a function of angle of attack, liquid water content, volume median drop diameter, temperature, and velocity. Ice accretions formed after five minutes of icing were shed in three minutes or less using a glycol fluid flow equal to the anti-ice flow rate. Two methods of predicting anti-ice flow rates are presented and compared with a large experimental data base of anti-ice flow rates over a wide range of icing conditions. The first method presented in the ADS-4 document typically predicts flow rates lower than the experimental flow rates. The second method, originally published in 1983, typically predicts flow rates up to 25 percent higher than the experimental flow rates. This method proved to be more consistent between wing-panel configurations. Significant correlation coefficients between the predicted flow rates and the experimental flow rates ranged from .867 to .947.

Albright, A. E.

1984-01-01

55

Dissipative corrections to particle spectra and anisotropic flow from a saddle-point approximation to kinetic freeze out  

E-print Network

A significant fraction of the changes in momentum distributions induced by dissipative phenomena in the description of the fluid fireball created in ultrarelativistic heavy-ion collisions actually take place when the fluid turns into individual particles. We study these corrections in the limit of a low freeze-out temperature of the flowing medium, and we show that they mostly affect particles with a higher velocity than the fluid. For these, we derive relations between different flow harmonics, from which the functional form of the dissipative corrections could ultimately be reconstructed from experimental data.

Christian Lang; Nicolas Borghini

2014-07-10

56

Freezing lake  

NSDL National Science Digital Library

Finite difference solution to mixed conduction-convection limited freezing of a 10 cm thick pool of water, with benchmark against analytical timescales. Requisite software: Gnumeric or Excel to open spreadsheets in source directory.

Powell, Adam C., IV

2005-02-23

57

Autobiographical Memory and Depression in the Later Age: The Bump Is a Turning Point  

ERIC Educational Resources Information Center

This preliminary study integrated previous findings of the distribution of autobiographical memories in the later age according to their age of occurrence, with the overgeneral memory bias predictive of depression. Twenty-five non-demented, Israeli participants between 65-89 years of age provided autobiographical memories to 4 groups of word cues…

Gidron, Yori; Alon, Shirly

2007-01-01

58

Boiling Point of Capillary-condensed Water  

Microsoft Academic Search

A CONSIDERABLE amount of experimental work on freezing-point depressions of capillary condensates has been reported in the literature in recent years1. Carman2 has given an account of a few more properties in which capillary-held liquids differ from the same materials in bulk conditions. Boiling points of condensates, however, do not appear to have been studied in detail. We have devised

M. L. Lakhanpal; B. R. Puri

1953-01-01

59

Satellite freeze forecast system  

NASA Technical Reports Server (NTRS)

Provisions for back-up operations for the satellite freeze forecast system are discussed including software and hardware maintenance and DS/1000-1V linkage; troubleshooting; and digitized radar usage. The documentation developed; dissemination of data products via television and the IFAS computer network; data base management; predictive models; the installation of and progress towards the operational status of key stations; and digital data acquisition are also considered. The d addition of dew point temperature into the P-model is outlined.

Martsolf, J. D. (principal investigator)

1983-01-01

60

Narrow depression in the density of states at the Dirac point in disordered graphene  

NASA Astrophysics Data System (ADS)

The electronic properties of noninteracting particles moving on a two-dimensional bricklayer lattice are investigated numerically. In particular, the influence of disorder in form of a spatially varying random magnetic flux is studied. In addition, a strong perpendicular constant magnetic field B is considered. The density of states ?(E) goes to zero for E?0 as in the ordered system but with a much steeper slope. This happens for both cases: at the Dirac point for B=0 and at the center of the central Landau band for finite B . Close to the Dirac point, the dependence of ?(E) on the system size, on the disorder strength, and on the constant magnetic flux density is analyzed and fitted to an analytical expression proposed previously in connection with the thermal quantum-Hall effect. Additional short-range on-site disorder completely replenishes the indentation in the density of states at the Dirac point.

Schweitzer, L.

2009-12-01

61

Depression, anxiety and their comorbidity in the Swedish general population: point prevalence and the effect on health-related quality of life  

PubMed Central

Background. Depression and anxiety disorders are major world-wide problems. There are no or few epidemiological studies investigating the prevalence of depression, generalized anxiety disorder and anxiety disorders in general in the Swedish population. Methods. Data were obtained by means of a postal survey administered to 3001 randomly selected adults. After two reminders response rate was 44.3%. Measures of depression and general anxiety were the 9-item Patient Health Questionnaire Depression Scale (PHQ-9) and the 7-item Generalized Anxiety Disorder Scale (GAD-7). The PHQ-9 identified participants who had experienced clinically significant depression (PHQ-9 ? 10), and who had a diagnosis of major depression (defined by using a PHQ-9 scoring algorithm). Clinically significant anxiety was defined as having a GAD-7 score ? 8. To specifically measure generalized anxiety disorder, the Generalized Anxiety Disorder Questionnaire-IV (GAD-Q-IV) was used with an established cut-off. Health-related quality of life was measured using the EuroQol (EQ-5D). Experiences of treatments for psychiatric disorders were also assessed. Results. Around 17.2% (95% CI: 15.1–19.4) of the participants were experiencing clinically significant depression (10.8%; 95% CI: 9.1–12.5) and clinically significant anxiety (14.7%; 95% CI: 12.7–16.6). Among participants with either clinically significant depression or anxiety, nearly 50% had comorbid disorders. The point prevalence of major depression was 5.2% (95% CI: 4.0–6.5), and 8.8% (95% CI: 7.3–10.4) had GAD. Among those with either of these disorders, 28.2% had comorbid depression and GAD. There were, generally, significant gender differences, with more women having a disorder compared to men. Among those with depression or anxiety, only between half and two thirds had any treatment experience. Comorbidity was associated with higher symptom severity and lower health-related quality of life. Conclusions. Epidemiological data from the Swedish community collected in this study provide point prevalence rates of depression, anxiety disorders and their comorbidity. These conditions were shown in this study to be undertreated and associated with lower quality of life, that need further efforts regarding preventive and treatment interventions. PMID:23862109

Carlbring, Per; Heedman, ?sa; Paxling, Björn; Andersson, Gerhard

2013-01-01

62

Involvement of protein synthesis in the reconsolidation of memory at different time points after formation of conditioned reflex freezing in mice  

Microsoft Academic Search

The aim of the present work was to study the involvement of protein synthesis in the reconsolidation of memory at different\\u000a periods of time after training. In mice trained in a conditioned reflex freezing model, memory was reactivated by a reminder\\u000a combined with administration of the protein synthesis inhibitor cycloheximide. The results showed that suppression of protein\\u000a synthesis on reactivation

E. V. Murav’eva; K. V. Anokhin

2007-01-01

63

Refrigeration Requirements for Ice Cream Freezing1  

Microsoft Academic Search

The heat removed from an ice cream mix during freezing is a function of several variables with composition predominating. This investigation compared experimental calorimetric results with predicted refrig- eration requirements. The predictions were obtained by adding the contributions of sensible heat of mix above the initial freezing point, sensible heat of unfrozen mix portion, latent heat and sensible heat of

D. R. Heldman; T. I. Hedrick

1970-01-01

64

Postpartum Depression  

MedlinePLUS

... postpartum depression? • When does postpartum depression occur? • What causes postpartum depression? • If I think I have postpartum depression, when ... College of Obstetricians and Gynecologists f AQ What causes postpartum depression? Postpartum depression probably is caused by a combination ...

65

Fundamentals of freeze-drying.  

PubMed

Given the increasing importance of reducing development time for new pharmaceutical products, formulation and process development scientists must continually look for ways to "work smarter, not harder." Within the product development arena, this means reducing the amount of trial and error empiricism in arriving at a formulation and identification of processing conditions which will result in a quality final dosage form. Characterization of the freezing behavior of the intended formulation is necessary for developing processing conditions which will result in the shortest drying time while maintaining all critical quality attributes of the freeze-dried product. Analysis of frozen systems was discussed in detail, particularly with respect to the glass transition as the physical event underlying collapse during freeze-drying, eutectic mixture formation, and crystallization events upon warming of frozen systems. Experiments to determine how freezing and freeze-drying behavior is affected by changes in the composition of the formulation are often useful in establishing the "robustness" of a formulation. It is not uncommon for seemingly subtle changes in composition of the formulation, such as a change in formulation pH, buffer salt, drug concentration, or an additional excipient, to result in striking differences in freezing and freeze-drying behavior. With regard to selecting a formulation, it is wise to keep the formulation as simple as possible. If a buffer is needed, a minimum concentration should be used. The same principle applies to added salts: If used at all, the concentration should be kept to a minimum. For many proteins a combination of an amorphous excipient, such as a disaccharide, and a crystallizing excipient, such as glycine, will result in a suitable combination of chemical stability and physical stability of the freeze-dried solid. Concepts of heat and mass transfer are valuable in rational design of processing conditions. Heat transfer by conduction--the dominant mechanism of heat transfer in freeze-drying--is inefficient at the pressures used in freeze-drying. Steps should be taken to improve the thermal contact between the product and the shelf of the freeze dryer, such as eliminating metal trays from the drying process. Quantitation of the heat transfer coefficient for the geometry used is a useful way of assessing the impact of changes in the system such as elimination of product trays and changes in the vial. Because heat transfer by conduction through the vapor increases with increasing pressure, the commonly held point of view that "the lower the pressure, the better" is not true with respect to process efficiency. The optimum pressure for a given product is a function of the temperature at which freeze-drying is carried out, and lower pressures are needed at low product temperatures. The controlling resistance to mass transfer is almost always the resistance of the partially dried solids above the submination interface. This resistance can be minimized by avoiding fill volumes of more than about half the volume of the container. The development scientist should also recognize that very high concentrations of solute may not be appropriate for optimum freeze-drying, particularly if the resistance of the dried product layer increases sharply with concentration. Although the last 10 years has seen the publication of a significant body of literature of great value in allowing development scientists and engineers to "work smarter," there is still much work needed in both the science and the technology of freeze-drying. Scientific development is needed for improving analytical methodology for characterization of frozen systems and freeze-dried solids. A better understanding of the relationship between molecular mobility and reactivity is needed to allow accurate prediction of product stability at the intended storage temperature based on accelerated stability at higher temperatures. This requires that the temperature dependence of glass transition-associated mobili

Nail, Steven L; Jiang, Shan; Chongprasert, Suchart; Knopp, Shawn A

2002-01-01

66

Avoid freeze-up of steam traps and their piping  

Microsoft Academic Search

This article addresses the problem of keeping steam traps free of ice in cold weather. The topics of the article include piping configurations and trap types that contribute to freezing, freeze damage, obstructions in piping, insulation of lines to retard freezing, common manifolds for heating of condensate, draining of low points, temperature-actuated devices, and water hammer damage.

OKeefe

1993-01-01

67

Avoid freeze-up of steam traps and their piping  

SciTech Connect

This article addresses the problem of keeping steam traps free of ice in cold weather. The topics of the article include piping configurations and trap types that contribute to freezing, freeze damage, obstructions in piping, insulation of lines to retard freezing, common manifolds for heating of condensate, draining of low points, temperature-actuated devices, and water hammer damage.

O'Keefe, W.

1993-12-01

68

Fish With Nature's Anti-freeze  

NSDL National Science Digital Library

Using this material, students will discover that under special experimental conditions, fish have been observed functioning in ice-free cold salt water at a temperature of -6 degrees Centigrade. Research has found that these fish have eight types of anti-freeze molecules which bathe the interior surface of their skin, acting as a barrier to ice propagating in from outside. When the anti-freeze molecules are not present, ice filters through their skin at these temperatures and crystallizes (freezes) their blood and tissues. Students will experiment with lowering the freezing point of a substance, thus causing it to remain liquid at a temperature when it is normally solid. Students will compare their findings with facts about Antarctic ice-fish, which have bodily fluids that remain liquid at temperatures below freezing.

69

The Effects of Social Economic Status, Social Support, Gender, Ethnicity and Grade Point Average on Depression among College Students.  

ERIC Educational Resources Information Center

Previous research has indicated that depression, the most common psychological disorder experienced by over 19 million Americans, can be related to such factors as ethnicity, social support, social economic status, academic achievement and gender. One hundred and sixty students from Johnson C. Smith University and Tennessee State University were…

Ndoh, Sunday; Scales, Josie

70

Winter Depression  

NSDL National Science Digital Library

A U.K. psychologist has developed a complex mathematical formula using seven variables to predict winter's emotional low point. The good news is the worst day of the year was last week; nonetheless, seasonal depression remains a problem for many. The first link (1) is to an article about the equation worked out by Dr. Cliff Arnall, who specializes in seasonal disorders at the University of Cardiff, Wales. The second link is to a WebMD page (2) about winter depression, often referred to as Seasonal Affective Disorder (SAD). The next link (3) is to a recent news story about the results of a five-year study that found, rather than antidepressant drug therapy or air ionizers, light box therapy is the best remedy for the seasonal condition. The fourth link is to a set of Frequently Asked Questions (4) about SAD offered by Columbia Presbyterian Medical Center in New York City. The fifth link, to the Winter Depression Research Group at the University of Tromso in Norway(5), explains why Norway is a natural SAD research laboratory. The next link is to a international portal site (6) maintained by medical professionals and researchers in the field of light therapy and biological rhythms. The final webpage(7), from Psychology Today, compares the symptoms of winter depression with summer depression.

71

Factors that influence freezing in the subAntarctic springtail Tullbergia antarctica  

Microsoft Academic Search

Effects of 12 biotic and abiotic factors on the freezing point of the sub-Antarctic springtail, Tullbergia antarctica, were investigated. Repeated cooling of individual springtails five times resulted in very similar freezing points suggesting that ice nucleation in this freeze-susceptible species is likely to be initiated by intrinsic factors rather than being a stochastic event. Mean supercooling point (SCP) was influenced

M. Roger Worland

2005-01-01

72

The importance of COâ on freezing point measurements of fluid inclusions: evidence from active geothermal systems and implications for epithermal ore deposition  

Microsoft Academic Search

The authors show how the melting point of ice may be calculated for a fluid of known composites. Fluid inclusion ice-melting data from New Zealand geothermal fields correlate well with values calculated using the equation presented and the measured compositions of discharges from wells from which the inclusion samples were obtained. Loss of the dominant dissolved gas, COâ during boiling

J. W. Hedenquist; R. W. Henley

1985-01-01

73

Surface freezing of n-octane nanodroplets  

NASA Astrophysics Data System (ADS)

Surface freezing, at temperatures up to a few degrees above the equilibrium melting point, has been observed for intermediate chain length (16? i? 50) n-alkanes [B. M. Ocko, X. Z. Wu, E. B. Sirota, S. K. Sinha, O. Gang and M. Deutsch, Phys. Rev. E, 1997, 55, 3164-3182]. Our recent experimental results suggest that surface freezing is also the first step when highly supercooled nanodroplets of n-octane crystallize. Our data yield surface and bulk nucleation rates on the order of ˜1015/cm2.s and ˜1022/cm3.s, respectively. Complementary molecular dynamics simulations also show that the surface of the droplet freezes almost immediately, and freezing of the remainder of the droplet progresses in a layer-by-layer manner.

Modak, Viraj; Pathak, Harshad; Thayer, Mitchell; Singer, Sherwin; Wyslouzil, Barbara

2013-05-01

74

Freeze drying apparatus  

DOEpatents

The present invention provides methods and apparatus for freeze drying in which a solution, which can be a radioactive salt dissolved within an acid, is frozen into a solid on vertical plates provided within a freeze drying chamber. The solid is sublimated into vapor and condensed in a cold condenser positioned above the freeze drying chamber and connected thereto by a conduit. The vertical positioning of the cold condenser relative to the freeze dryer helps to help prevent substances such as radioactive materials separated from the solution from contaminating the cold condenser. Additionally, the system can be charged with an inert gas to produce a down rush of gas into the freeze drying chamber to also help prevent such substances from contaminating the cold condenser.

Coppa, Nicholas V. (Malvern, PA); Stewart, Paul (Youngstown, NY); Renzi, Ernesto (Youngstown, NY)

2001-01-01

75

Freeze drying method  

DOEpatents

The present invention provides methods and apparatus for freeze drying in which a solution, which can be a radioactive salt dissolved within an acid, is frozen into a solid on vertical plates provided within a freeze drying chamber. The solid is sublimated into vapor and condensed in a cold condenser positioned above the freeze drying chamber and connected thereto by a conduit. The vertical positioning of the cold condenser relative to the freeze dryer helps to help prevent substances such as radioactive materials separated from the solution from contaminating the cold condenser. Additionally, the system can be charged with an inert gas to produce a down rush of gas into the freeze drying chamber to also help prevent such substances from contaminating the cold condenser.

Coppa, Nicholas V. (Malvern, PA); Stewart, Paul (Youngstown, NY); Renzi, Ernesto (Youngstown, NY)

1999-01-01

76

Preparation of porous scaffolds by using freeze-extraction and freeze-gelation methods.  

PubMed

Freeze-fixation and freeze-gelation methods are presented in this paper which can be used to prepare highly porous scaffolds without using the time and energy consuming freeze-drying process. The porous structure was generated during the freeze of a polymer solution, following which either the solvent was extracted by a non-solvent or the polymer was gelled under the freezing condition; thus, the porous structure would not be destructed during the subsequent drying stage. Compared with the freeze-drying method, the presented methods are time and energy-saving, with less residual solvent, and easier to be scaled up. Besides, the problem of formation of surface skin can be resolved and the limitation of using solvent with low boiling point can be lifted by the presented methods. With the freeze-extraction and freeze-gelation methods, porous PLLA, PLGA, chitosan and alginate scaffolds were successfully fabricated. In addition to the presentation of the morphologies of the fabricated scaffolds, preliminary data of cell culture on them are as well included in the present work. PMID:14580916

Ho, Ming-Hua; Kuo, Pei-Yun; Hsieh, Hsyue-Jen; Hsien, Tzu-Yang; Hou, Lein-Tuan; Lai, Juin-Yih; Wang, Da-Ming

2004-01-01

77

H, not O or pressure, causes eutectic T depression in the Fe-FeS System to 8 GPa  

NASA Astrophysics Data System (ADS)

The Fe-FeS system maintains a eutectic temperature of 990 ± 10 °C to at least 8 GPa if starting materials and pressure media are rigorously dehydrated. Literature reports of pressure-induced freezing point depression of the eutectic for the Fe-FeS system are not confirmed. Modest addition of oxygen alone is confirmed to cause negligible freezing point depression at 6 GPa. Addition of H alone causes a progressive decrease in the eutectic temperature with P in the Fe-FeS-H system to below 965 °C at 6 GPa to below 950 °C at 8 GPa. It is our hypothesis that moisture contamination in unrigorously dried experiments may be an H source for freezing point depression. O released from H2O disproportionation reacts with Fe and is sequestered as ferropericlase along the sample capsules walls, leaving the H to escape the system and/or enter the Fe-FeS mixture. The observed occurrence of ferropericlase on undried MgO capsule margins is otherwise difficult to explain, because an alternate source for the oxygen in the ferropericlase layer is difficult to identify. This study questions the use of pressure-depressed Fe-S eutectic temperatures and suggests that the lower eutectic temperatures sometimes reported are achieved by moving into the ternary Fe-S-H system. These results adjust slightly the constraints on eutectic temperatures allowed for partly solidified cores on small planets. H substantially diminishes the temperature extent of the melting interval in Fe-S by reducing the melting points of the crystalline phases more than it depresses the eutectic.

Buono, Antonio S.; Walker, David

2014-12-01

78

Freezing in Halide Salts  

NASA Astrophysics Data System (ADS)

The static criterion that the amplitude of the principal peak of the liquid structure factor has a constant value along the freezing line and the onset of freezing are studied from the structure factors and the static dielectric functions of halide salts interacting via the effective pair potentials through the hypernetted-chain approximation. It is observed that the criterion above is restricted to the effective charge difference. The critical value of plasma parameter at freezing is affected by the mobility and number concentration of anions and cations. The distribution of the value of the static dielectric function closest to the wave number axis in the negative region is also determined by the charge difference and the ordering of ions and related to the onset of freezing.

Akdere, ?.; Y?lmaz, M.; Kavanoz, H. B.; Ta?seven, Ç.

2008-06-01

79

Freeze-fracture cytochemistry in cell biology.  

PubMed

The term freeze-fracture cytochemistry embraces a series of techniques which share the goal of chemical identification of the structural components viewed in freeze-fracture replicas. As one of the major features of freeze fracture is its ability to provide planar views of membranes, a major emphasis in freeze-fracture cytochemistry is to identify integral membrane proteins, study their spatial organization in the membrane plane, and examine their role in dynamic cellular processes. Effective techniques in freeze-fracture cytochemistry, of wide application in cell biology, are now available. These include fracture-label, label fracture, and the freeze-fracture replica immunolabeling technique (FRIL). In fracture-label, samples are frozen and fractured, thawed for labeling, and finally processed for viewing either by critical-point drying and platinum-carbon replication or by thin-section electron microscopy. Label-fracture involves immunogold labeling a cell suspension, processing as for standard freeze-fracture replication, and then examining the replica without removal of the cellular components. Of greatest versatility, however, is the FRIL technique, in which samples are frozen, fractured, and replicated with platinum-carbon as in standard freeze fracture, and then carefully treated with sodium dodecylsulphate (SDS) to remove all the biological material except a fine layer of molecules attached to the replica itself. Immunogold labeling of these molecules permits the distribution of identified components to be viewed superimposed upon high resolution planar views of replicated membrane structure, for both the plasma membrane and intracellular membranes in cells and tissues. Examples of how these techniques have contributed to our understanding of cardiovascular cell function in health and disease are discussed. PMID:18617035

Severs, Nicholas J; Robenek, Horst

2008-01-01

80

Membranes and MEAs at Freezing Temperatures Thomas A. Zawodzinski, Jr.  

E-print Network

Membranes and MEAs at Freezing Temperatures Thomas A. Zawodzinski, Jr. Case Western Reserve #12;5 Conductivity of Membrane at Low T Conductivity drops dramatically below freezing point Note that ~ 6 and increasingly tightly bound as decreases #12;9 DSC thermograms of PEFC membranes (water

81

Freezing and melting water in lamellar structures.  

PubMed Central

The manner in which ice forms in lamellar suspensions of dielaidoylphosphatidylethanolamine, dielaidoylphosphatidylcholine, and dioleoylphosphatidylcholine in water depends strongly on the water fraction. For weight fractions between 15 and 9%, the freezing and melting temperatures are significantly depressed below 0 degree C. The ice exhibits a continuous melting transition spanning as much as 20 degrees C. When the water weight fraction is below 9%, ice never forms at temperatures as low as -40 degrees C. We show that when water contained in a lamellar lipid suspension freezes, the ice is not found between the bilayers; it exists as pools of crystalline ice in equilibrium with the bound water associated with the polar lipid headgroups. We have used this effect, together with the known chemical potential of ice, to measure hydration forces between lipid bilayers. We find exponentially decaying hydration repulsion when the bilayers are less than about 7 A apart. For larger separations, we find significant deviations from single exponential decay. PMID:7948683

Gleeson, J T; Erramilli, S; Gruner, S M

1994-01-01

82

High-freezing-point fuel studies  

NASA Technical Reports Server (NTRS)

Considerable progress in developing the experimental and analytical techniques needed to design airplanes to accommodate fuels with less stringent low temperature specifications is reported. A computer technique for calculating fuel temperature profiles in full tanks was developed. The computer program is being extended to include the case of partially empty tanks. Ultimately, the completed package is to be incorporated into an aircraft fuel tank thermal analyser code to permit the designer to fly various thermal exposure patterns, study fuel temperatures versus time, and determine holdup.

Tolle, F. F.

1980-01-01

83

Polymerization with freezing  

NASA Astrophysics Data System (ADS)

Irreversible aggregation processes involving reactive and frozen clusters are investigated using the rate equation approach. In aggregation events, two clusters join irreversibly to form a larger cluster; additionally, reactive clusters may spontaneously freeze. Frozen clusters do not participate in merger events. Generally, freezing controls the nature of the aggregation process, as demonstrated by the final distribution of frozen clusters. The cluster mass distribution has a power-law tail, Fk~k-?, when the freezing process is sufficiently slow. Different exponents, ? = 1 and 3, are found for the constant and the product aggregation rates, respectively. For the latter case, the standard polymerization model, either no gels, or a single gel, or even multiple gels, may be produced.

Ben-Naim, E.; Krapivsky, P. L.

2005-12-01

84

Report to the CCT on COOMET comparison COOMET.T-K3.1 (previously COOMET.T-S1): Key regional comparison of the national standards of temperature in the range from the triple point of water to the freezing point of zinc  

NASA Astrophysics Data System (ADS)

In the framework of the CIPM MRA, a first COOMET comparison "Comparison of the ITS-90 realizations in the range from 0.01 °C to 429.7485 °C (from the triple point of water to the freezing point of zinc)", registered in the KCDB under the identifier "COOMET.T-K3", was carried out in 2005-2007. Four national metrology institutes took part in this comparison: VNIIM (Russian Federation), SMU (Slovakia), BelGIM (Republic of Belarus) and NSC IM (Ukraine), and two of them (VNIIM and SMU) ensured the linkage with key comparisons CCT-K3 and CCT-K4, in order to disseminate the metrological equivalence to the measurement standards of NSC IM and BelGIM. NSC IM, however, had to withdraw its results, and at the meeting of Technical Committee T-10 of COOMET it was decided to carry out a supplementary bilateral comparison between VNIIM and the NSC IM for realization of the ITS-90 in the same range of temperature. This was registered in the KCDB under the identifier COOMET.T-S1 and measurements were performed in 2008-2009. From the results presented in this report, it is possible to draw the conclusion that the COOMET supplementary comparison COOMET.T-S1 demonstrates the CMC uncertainties claimed by the NSC IM for the melting point of gallium 0.236 mK (k = 2), and the freezing points of indium 1.040 mK (k = 2), tin 0.858 mK (k = 2) and zinc 0.944 mK (k = 2). In September 2012 the Working Group on key Comparisons (WG 7) of the CCT upgraded this comparison to a COOMET key comparison of the 'CCT-K3' type. It is now identified as COOMET.T-K3.1. In April 2013 this report was superseded by item 03006 in the Technical Supplement of 2013. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

Pokhodun, A. I.

2010-01-01

85

The freezing rotation illusion  

Microsoft Academic Search

The “freezing rotation illusion” refers to decrease in perceived speed of a continuously rotating central region when a swaying surround co-rotates. We observed the following effects for rotations: First, when the centre and its surround are turning in the same direction, and their velocities are distinguishable, the perceived speed of the centre is lower than its physical speed. Second, when

Max R. Dürsteler

2008-01-01

86

Animal Anti-Freeze  

NSDL National Science Digital Library

In this outdoor winter activity, learners search for and create hibernation sites that will protect gelatin "animals" from freezing. Learners come to understand that hibernating animals need to take care in selecting a sleeping spot that will provide protection from the winter cold.

Science, Lawrence H.

1982-01-01

87

FREEZE FRAMING MUSLIMS  

Microsoft Academic Search

Western images of Islam and Muslims have been frozen in history and are recycled with mundane regularity. These ‘freeze frames’ emerged at the beginning of Islam and have, over centuries, acquired certain key elements and descriptors. Association of Islam with promiscuity and licentiousness was common during the eight and tenth centuries. The Crusades added war-like violence to the picture, and

Ziauddin Sardar; Merryl Wyn Davies

2010-01-01

88

Modeling soil freezing dynamics  

Technology Transfer Automated Retrieval System (TEKTRAN)

Seasonally frozen soil strongly influences runoff and erosion on large areas of land around the world. In many areas, rain or snowmelt on seasonally frozen soil is the single leading cause of severe runoff and erosion events. As soils freeze, ice blocks the soil pores, greatly diminishing the permea...

89

[Severe depression : psychoanalysis].  

PubMed

The indication for psychoanalysis in severe depression is not clear. And yet, demands for this type of intervention are increasing, despite the absence of any form of consensus on the subject. Freud considered depression as a failure of analytical efforts and, based on this observation, revised his theory, in particular to include the notions of narcissism and the death drive. Many analysts have been reluctant to follow his teachings on this last point and provide depressed patients with analytical-type therapies aimed at restoring narcissism. Melanie Klein pushed Freud's ideas about depression even further and brought such therapies back to the heart of analytical practice. Jacques Lacan took the debate to another level by proposing an overhaul of the principles on which analysis has been based. Today, while following certain precautionary rules, true psychoanalyses can be proposed to patients with severe depression, whether of the bipolar, recurring or even neurotic type that can reach this level of severity. PMID:20141799

Bouvet de la Maisonneuve, O

2009-12-01

90

Freeze-drying of proteins.  

PubMed

Freeze-drying has become one of the most important processes for the preservation of biological products. This chapter provides protocols for freeze-drying of proteins and discusses the importance of formulation, cycle development, and validation. Specific formulations for stabilization of proteins are presented as well as advice on common problems with freeze-drying of proteins. PMID:25428023

Liu, Baolin; Zhou, Xinli

2015-01-01

91

Seasonal accumulation of acetylated triacylglycerols by a freeze-tolerant insect.  

PubMed

Most animals store energy as long-chain triacylglycerols (lcTAGs). Trace amounts of acetylated triacylglycerols (acTAGs) have been reported in animals, but are not accumulated, likely because they have lower energy density than lcTAGs. Here we report that acTAGs comprise 36% of the neutral lipid pool of overwintering prepupae of the goldenrod gall fly, Eurosta solidaginis, while only 17% of the neutral lipid pool is made up of typical lcTAGs. These high concentrations of acTAGs, present only during winter, appear to be synthesized by E. solidaginis and are not found in other freeze-tolerant insects, nor in the plant host. The mixture of acTAGs found in E. solidaginis has a significantly lower melting point than equivalent lcTAGs, and thus remains liquid at temperatures at which E. solidaginis is frozen in the field, and depresses the melting point of aqueous solutions in a manner unusual for neutral lipids. We note that accumulation of acTAGs coincides with preparation for overwintering and the seasonal acquisition of freeze tolerance. This is the first observation of accumulation of acTAGs by an animal, and the first evidence of dynamic interconversion between acTAGs and lcTAGs during development and in response to stress. PMID:24790101

Marshall, Katie E; Thomas, Raymond H; Roxin, Aron; Chen, Eric K Y; Brown, Jason C L; Gillies, Elizabeth R; Sinclair, Brent J

2014-05-01

92

Inactivation of Kudoa septempunctata in olive flounder meat by liquid freezing.  

PubMed

Kudoa septempunctata in olive flounder meat was inactivated using 3 distinct freezing methods?liquid freezing for 5 min, air blast freezing at ?30? for 5 h, and ?80? for 1 h. The fracture curve of olive flounder meat subjected to liquid freezing resembled that of meat stored at 4?, indicating that the structure of olive flounder muscle was well preserved. In contrast, air blast freezing induced the disappearance of the fracture point in the fracture curve, indicating that there was deterioration in the meat quality. Liquid freezing preserved the transparency of olive flounder meat to the same degree as that of meat stored at 4°C. However, air blast freezing induced meat cloudiness. These results indicate that liquid freezing can be used for K. septempunctata inactivation without affecting the meat quality. PMID:25252645

Ohnishi, Takahiro; Akuzawa, Sayuri; Furusawa, Hiroko; Yoshinari, Tomoya; Kamata, Yoichi; Sugita-Konishi, Yoshiko

2014-01-01

93

The freezing bomb  

NASA Astrophysics Data System (ADS)

The extreme pressures that are generated when water freezes were traditionally demonstrated by sealing a small volume in a massive cast iron 'bomb' and then surrounding it with a freezing mixture of ice and salt. This vessel would dramatically fail by brittle fracture, but no quantitative measurement of bursting pressure was available. Calculation suggests a maximum of about 55 MPa (8000 psi) might have been achieved, with some 2.3% of the water frozen into a hollow shell around the interior of the vessel. In a sufficiently strong alloy steel container the pressure might rise to a maximum of 210 MPa (30 460 psi), this limiting figure being due to the collapse of ordinary ice (ice I) to the denser forms ice II or ice III.

Mills, Allan

2010-03-01

94

Mechanisms of Freezing lnjuly in Cellular Leve  

NASA Astrophysics Data System (ADS)

The mechanisms of freezing injury in living cells were reviewed. The freezing injury takes place by at least two different factors depending upon cooling rate, those are intracellular freezing and extracellular freezing. The freezing injury caused by extracellular freezing also takes place by two different factors, those are direct and indirect effects by the formation of extracellular ice. These different stresses by freezing cause different damages on the plasma membranes in the same cell. Furthermore, freezing of different cell results in different form of membrane damage. Thus, the occurrence of freezing injury takes place by diverse mechanisms depending upon not only different freezing stresses but also difference of cell type.

Fujikawa, Seizo

95

Freezing of Water Droplet due to Evaporation  

NASA Astrophysics Data System (ADS)

In this study, the feasibility of cooling/freezing of phase change.. materials(PCMs) due to evaporation for cold storage systems was experimentally examined. A pure water was used as the test PCM, since the latent heat due to evaporation of water is about 7 times larger than that due to freezing. A water droplet, the diameter of which was 1-4 mm, was suspended in a test cell by a fine metal wire (O. D.= 100?m),and the cell was suddenly evacuated up to the pressure lower than the triple-point pressure of water, so as to enhance the evaporation from the water surface. Temperature of the droplet was measured by a thermocouple, and the cooling/freezing behavior and the temperature profile of the droplet surface were captured by using a video camera and an IR thermo-camera, respectively. The obtained results showed that the water droplet in the evacuated cell is effectively cooled by the evaporation of water itself, and is frozen within a few seconds through remarkable supercooling state. When the initial temperature of the droplet is slightly higher than the room temperature, boiling phenomena occur in the droplet simultaneously with the freezing due to evaporation. Under such conditions, it was shown that the degree of supercooling of the droplet is reduced by the bubbles generated in the droplet.

Satoh, Isao; Fushinobu, Kazuyoshi; Hashimoto, Yu

96

Freezing in the Antarctic limpet, Nacella concinna.  

PubMed

The process of organismal freezing in the Antarctic limpet, Nacella concinna, is complicated by molluscan biology. Internal ice formation is, in particular, mediated by two factors: (a) the provision of an inoculative target for ice formation in the exposed mucus-secreting foot; and (b) osmoconformity to the marine environment. With regard to the first, direct observations of the independent freezing of pedal mucus support the hypothesis that internal ice formation is delayed by the mucal film. As to the second, ice nucleation parametrics of organismal tissue (head, midgut, gonad, foot) and mucus in both inter- and subtidal populations were characterized by high melting points (range=-4.61 to -6.29 degrees C), with only c.50% of a given sample osmotically active. At this stage it would be premature to ascribe a cryo-adaptive function to the mucus as the protective effects are more readily attributed to the physical properties of the secretion (i.e. viscosity) and their corresponding effects on the rate of heat transfer. As it is difficult to thermally distinguish between the freezing of mucus and the rest of the animal, the question as to whether it is tolerant of internal as well as external ice formation remains problematic, although it may be well suited to the osmotic stresses of organismal freezing. PMID:20599885

Hawes, T C; Worland, M R; Bale, J S

2010-08-01

97

Freeze-Tolerant Condensers  

NASA Technical Reports Server (NTRS)

Two condensers designed for use in dissipating heat carried by working fluids feature two-phase, self-adjusting configurations such that their working lengths automatically vary to suit their input power levels and/or heat-sink temperatures. A key advantage of these condensers is that they can function even if the temperatures of their heat sinks fall below the freezing temperatures of their working fluids and the fluids freeze. The condensers can even be restarted from the frozen condition. The top part of the figure depicts the layout of the first condenser. A two-phase (liquid and vapor) condenser/vapor tube is thermally connected to a heat sink typically, a radiatively or convectively cooled metal panel. A single-phase (liquid) condensate-return tube (return artery) is also thermally connected to the heat sink. At intervals along their lengths, the condenser/vapor tube and the return artery are interconnected through porous plugs. This condenser configuration affords tolerance of freezing, variable effective thermal conductance (such that the return temperature remains nearly constant, independently of the ultimate sink temperature), and overall pressure drop smaller than it would be without the porous interconnections. An additional benefit of this configuration is that the condenser can be made to recover from the completely frozen condition either without using heaters, or else with the help of heaters much smaller than would otherwise be needed. The second condenser affords the same advantages and is based on a similar principle, but it has a different configuration that affords improved flow of working fluid, simplified construction, reduced weight, and faster recovery from a frozen condition.

Crowley, Christopher J.; Elkouhk, Nabil

2004-01-01

98

Freezing of Nonwoody Plant Tissue  

PubMed Central

Temperature recordings of the freezing of plant tissues include two plateaus or regions of reduced slope. During the second of these, small positive spikes were observed. When a completely frozen tissue was thawed and refrozen, neither the second plateau nor the spikes were recorded. Both were present, however, if the initial freezing had been terminated before the second plateau had been reached. The spikes appear to represent the release of heat of crystallization during the freezing of individual cells. Such a freezing and thawing cycle destroys the ability of the cells to remain supercooled in the presence of the ice that is formed as the first plateau is recorded. PMID:16658774

Brown, M. S.; Pereira, E. Sa B.; Finkle, Bernard J.

1974-01-01

99

Performance Characteristics of an Isothermal Freeze Valve  

SciTech Connect

This document discusses performance characteristics of an isothermal freeze valve. A freeze valve has been specified for draining the DWPF melter at the end of its lifetime. Two freeze valve designs have been evaluated on the Small Cylindrical Melter-2 (SCM-2). In order to size the DWPF freeze valve, the basic principles governing freeze valve behavior need to be identified and understood.

Hailey, A.E.

2001-08-22

100

Depression overview.  

PubMed

Depression is a common condition that often remains undiagnosed and untreated; however, symptoms are more likely to be recognized today than in past decades. Survey data suggest that female, nonwhite patients are more likely to report depressive symptoms, especially those who are less educated, poor, and covered by Medicaid. Depression may be a finding suggestive of dysthymic disorder, minor or major depressive disorder, seasonal affective disorder, episodic depression, or a sign of an associated mood disorder, such as bipolar disorder. Many effective treatments are available that are well tolerated. This article outlines the diagnostic approach used in primary care, as well as the different treatment options available for this condition. Depression can have serious consequences and must be treated appropriately. PMID:25126224

McCarter, Thomas

2008-04-01

101

Freezing and thawing porous media: experimental study with a dielectric capacitive method  

NASA Astrophysics Data System (ADS)

A capacitive sensor-based apparatus has been used to study the ice/water phase change in consolidated porous media subjected to freezing and thawing. This technique relies on the dielectric properties of water, ice, air, and the mineral substrate in the radio-frequency range. It gives directly the freezing and thawing temperature depressions and indirectly provides an estimation of pore size distribution through the Gibbs-Thomson relation. It also holds good promise for evaluating the amount of liquid water in frozen porous media by combining drying and freezing tests. To cite this article: T. Fen-Chong, A. Fabbri, C. R. Mecanique 333 (2005).

Fen-Chong, Teddy; Fabbri, Antonin

2005-05-01

102

Thermal properties of ration components as affected by moisture content and water activity during freezing.  

PubMed

Beef roast with vegetables is an example of a meal, ready-to-eat (MRE) ration entrée. It is a mixture of meat, potato, mushroom, and carrot with a gravy sauce. The thermal properties of each component were characterized in terms of freezing point, latent heat, freezable and unfreezable water contents, and enthalpy during freezing using differential scanning calorimetry. Freezing and thawing curves and the effect of freezing and thawing cycles on thermal properties were also evaluated. The freezing points of beef, potato, mushroom, and sauce were all in the range of -5.1 to -5.6 degrees C, but moisture content, water activity, latent heat, freezable and unfreezable water contents, and enthalpy varied among these components. Freezing temperature greatly affected the unfrozen water fraction. The unfreezable water content (unfrozen water fraction at -50 degrees C) of ration components was in the range of 8.2% to 9.7%. The freezing and thawing curves of vegetables with sauce differed from those of beef but took similar time to freeze or thaw. Freezing and thawing cycles did not greatly affect the thermal properties of each component. Freezing point and latent heat were reduced by decreasing moisture content and water activity of each component. Water activity was proportionally linear to freezing point at a(w) > 0.88, and moisture content was proportionally linear to freezable water content in all ration components. Water was not available for freezing when moisture content was reduced to 28.8% or less. This study indicates that moisture content and water activity are critical factors affecting thermal behavior of ration components during freezing. PMID:19021797

Li, J; Chinachoti, P; Wang, D; Hallberg, L M; Sun, X S

2008-11-01

103

Infrared spectroscopy of sulfuric acid/water aerosols: Freezing characteristics  

NASA Astrophysics Data System (ADS)

A low-temperature flow cell has been used in conjunction with a Fourier transform infrared (FT-IR) spectrometer to study sulfuric acid/water aerosols. The aerosols were generated with a wide range of composition (28 to 85 wt%), including those characteristic of stratospheric sulfate aerosols, and studied over the temperature range from 240 K to 160 K. The particles exhibited deep supercooling, by as much as 100 K below the freezing point in some cases. Freezing of water ice was observed in the more dilute (<40 wt% sulfuric acid) particles, in agreement with the predictions of Jensen et al. and recent observations by Bertram et al. In contrast with theoretical predictions, however, the entire particle often does not immediately freeze, at least on the timescale of the present experiments (seconds to minutes). Freezing of the entire particle is observed at lower temperatures, well below that characteristic of the polar stratosphere.

Clapp, M. L.; Niedziela, R. F.; Richwine, L. J.; Dransfield, T.; Miller, R. E.; Worsnop, D. R.

1997-04-01

104

Repeated freezing induces oxidative stress and reduces survival in the freeze-tolerant goldenrod gall fly, Eurosta solidaginis.  

PubMed

Freeze tolerant insects must not only survive extracellular ice formation but also the generation of reactive oxygen species (ROS) during oxygen reperfusion upon thawing. Furthermore, diurnal fluctuations in temperature place temperate insects at risk of being exposed to multiple freeze-thaw cycles, yet few studies have examined metrics of survival and oxidative stress in freeze-tolerant insects subjected to successive freezing events. To address this, we assessed survival in larvae of the goldenrod gall fly Eurosta solidaginis, after being subjected to 0, 5, 10, 20, or 30 diurnally repeated cold exposures (RCE) to -18°C or a single freeze to -18°C for 20days. In addition, we measured indicators of oxidative stress, levels of cryoprotectants, and total aqueous antioxidant capacity in animals exposed to the above treatments at 8, 32, or 80h after their final thaw. Repeated freezing and thawing, rather than time spent frozen, reduced survival as only 30% of larvae subjected to 20 or 30 RCE successfully pupated, compared to those subjected to fewer RCE or a single 20d freeze, of which 82% pupated. RCE had little effect on the concentration of the cryoprotectant glycerol (4.26±0.66?gglycerol·ngprotein(-1) for all treatments and time points) or sorbitol (18.8±2.9?gsorbitol·mgprotein(-1) for all treatments and time points); however, sorbitol concentrations were more than twofold higher than controls (16.3±2.2?gsorbitol·mgprotein(-1)) initially after a thaw in larvae subjected to a single extended freeze, but levels returned to values similar to controls at 80h after thaw. Thawing likely produced ROS as total aqueous antioxidant capacities peaked at 1.8-fold higher than controls (14.7±1.6mmoltrolox·ngprotein(-1)) in animals exposed to 5, 10, or 20 RCE. By contrast, aqueous antioxidant capacities were similar to controls in larvae subjected to 30 RCE or the single 20d freeze regardless of time post final thaw, indicating these animals may have had an impaired ability to produce primary antioxidants. Larvae lacking an antioxidant response also had elevated levels of oxidized proteins, nearly twice that of controls (21.8±3.2mmolchloramine-T·mgprotein(-1)). Repeated freezing also lead to substantial oxidative damage to lipids that was independent of aqueous antioxidant capacity; peroxides were, on average, 5.6-fold higher in larvae subjected to 10, 20 or 30 RCE compared to controls (29.1±7.3mmolTMOP·?gprotein(-1)). These data suggest that oxidative stress due to repeated freeze-thaw cycles reduces the capacity of E. solidaginis larvae to survive freezing. PMID:24910457

Doelling, Adam R W; Griffis, Nicole; Williams, Jason B

2014-08-01

105

Freezing of living cells  

SciTech Connect

It can be calculated that a living cell will survive more than 5000 years at -196/sup 0/C. This ability to essentially stop biological time has important implications in medicine and agriculture, and in biological research. In medicine the chief implications are in the banking of transplantable tissues and organs and in in vitro fertilization. In agriculture the applications stem in part from the role of frozen embryos in amplifying the number of calves produced by high quanlity cows. The problem is how can cells survive both the cooling to such very low temperatures and the return to normal temperatures. The answers involve fundamental characteristics of cells such as the permeability of their surface membranes to water and solutes. These characteristics determine whether or not cells undergo lethal internal ice formation and other response during freezing and thawing. 27 refs., 12 figs.

Mazur, P.

1985-01-01

106

Treating Depression  

ERIC Educational Resources Information Center

In varying degrees, depression affects an estimated 60,000,000 Americans at any given time and is the most common emotional symptom seen by psychiatrists. Edward J. Stainbrrok, professor and chairman of the Department of Human Behavior, University of Southern California, comments on the causes and treatment of depression. (Editor/RK)

Intellect, 1977

1977-01-01

107

Freezing Poultry for Home Use  

E-print Network

. ? As you work, keep the cutting surface and utensils clean. ? Work quickly and place the poultry in the freezer as quickly as possible. ? Do not let raw poultry juices contaminate ready-to-eat foods. Answering the following questions will help you decide.... Since most homes do not have a quick-freeze unit and since poultry meat freezes slowly in a regular freezer, use these tips to help your poultry freeze faster. n If you use home-processed poultry, put it in an ice slush bath to chill the carcass...

Davis, Michael

2006-08-31

108

A NEW FREEZING-ULTRAMICROTOME  

PubMed Central

The difficulties in sectioning frozen biological objects for electron microscopic investigations are overcome by Steere's freezing-etching method. In order to test this method and to open up a wide field of application, the new freezing-ultramicrotome has been designed. The apparatus consists of the combination of an ultramicrotome with freezing-drying and shadow-casting installations in the same vacuum container. The preliminary results show, on the one hand, the practicability of all preparational steps and, on the other, that it is possible to resolve internal structures of cell organelles and even macromolecular patterns. PMID:13772269

Moor, H.; Mühlethaler, K.; Waldner, H.; Frey-Wyssling, A.

1961-01-01

109

Major depression.  

PubMed

Major depression is a common, disabling condition seen frequently in primary care practices. Non-psychiatrist ambulatory providers are increasingly responsible for diagnosing, and primarily managing patients suffering from major depressive disorder (MDD). The goal of this review is to help primary care providers to understand the natural history of MDD, identify practical tools for screening, and a thoughtful approach to management. Clinically challenging topics like co-morbid conditions, treatment resistant depression and pharmacotherapy selection with consideration to side effects and medication interactions, are also covered. PMID:25134869

Bentley, Susan M; Pagalilauan, Genevieve L; Simpson, Scott A

2014-09-01

110

Depression (lesson)  

NSDL National Science Digital Library

Students reveal their preconceptions about depression, then use G2C Online to learn about symptoms of the disorder, genes, and neurotransmitters associated with it, and challenges involved in diagnosis and treatment.

2009-04-14

111

Depression Rates  

MedlinePLUS Videos and Cool Tools

... December 4, 2014 Related MedlinePlus Pages Depression Health Statistics Transcript Nearly 8% of Americans report having moderate ... data released by the National Center for Health Statistics. The data were collected through symptom-based questionnaires ...

112

Postpartum Depression  

MedlinePLUS

... How is postpartum depression different from the “baby blues”? The “baby blues” is a term used to describe the feelings ... about, or tired from, providing that care. Baby blues, which affects up to 80 percent of mothers, ...

113

Screening for postnatal depression in primary care: cost effectiveness analysis  

Microsoft Academic Search

Objective To evaluate the cost effectiveness of routine screening for postnatal depression in primary care.Design Cost effectiveness analysis with a decision model of alternative methods of screening for depression, including standardised postnatal depression and generic depression instruments. The performance of screening instruments was derived from a systematic review and bivariate meta-analysis at a range of instrument cut points; estimates of

Mike Paulden; Stephen Palmer; Catherine Hewitt; Simon Gilbody

2009-01-01

114

Exposing a dynamical signature of the freezing transition through the sound propagation gap  

NASA Astrophysics Data System (ADS)

The conventional view of freezing holds that nuclei of the crystal phase form in the metastable fluid through purely stochastic thermal density fluctuations. The possibility of a change in the character of the fluctuations as the freezing point is traversed is beyond the scope of this perspective. Here we show that this perspective may be incomplete by examination of the time autocorrelation function of the longitudinal current, computed by molecular dynamics for the hard-sphere fluid around its freezing point. In the spatial window where sound is overdamped, we identify a change in the long-time decay of the correlation function at the known freezing points of monodisperse and moderately polydisperse systems. The fact that these findings agree with previous experimental studies of colloidal systems in which particle are subject to diffusive dynamics, suggests that the dynamical signature we identify with the freezing transition is a consequence of packing effects alone.

Martinez, V. A.; Zaccarelli, E.; Sanz, E.; Valeriani, C.; van Megen, W.

2014-11-01

115

Exposing a dynamical signature of the freezing transition through the sound propagation gap.  

PubMed

The conventional view of freezing holds that nuclei of the crystal phase form in the metastable fluid through purely stochastic thermal density fluctuations. The possibility of a change in the character of the fluctuations as the freezing point is traversed is beyond the scope of this perspective. Here we show that this perspective may be incomplete by examination of the time autocorrelation function of the longitudinal current, computed by molecular dynamics for the hard-sphere fluid around its freezing point. In the spatial window where sound is overdamped, we identify a change in the long-time decay of the correlation function at the known freezing points of monodisperse and moderately polydisperse systems. The fact that these findings agree with previous experimental studies of colloidal systems in which particle are subject to diffusive dynamics, suggests that the dynamical signature we identify with the freezing transition is a consequence of packing effects alone. PMID:25429604

Martinez, V A; Zaccarelli, E; Sanz, E; Valeriani, C; van Megen, W

2014-01-01

116

TISSUE FREEZING METHODS FOR CRYOSTAT SECTIONING  

E-print Network

that replaces the architecture with a "Swiss Cheese" effect. #12;The object is to freeze so rapidly that water ON THE SUBJECT OF WATER CRYSTAL FORMATION: "FREEZING BIOLOGICAL SAMPLES" Charles W. Scouten & Miles Cunningham OF TISSUE FREEZING 1. Fresh tissue freezing ­ Tissue is in OCT and flash frozen fresh. 2. 4% PFA fixed

Chisholm, Rex L.

117

The Identification of Postpartum Depression  

PubMed Central

Postpartum depression (PPD) is the most common medical complication of childbearing. Universal screening maximizes the likelihood of prompt identification of PPD. Obstetrician-gynecologists routinely evaluate postpartum women for a general health examination and review of family planning options at approximately 6 weeks after birth; therefore, they are well-positioned to identify PPD. In this paper, we review the diagnostic criteria for postpartum depressive disorders and clinical risk factors predictive of PPD. We examine depression screening tools, appropriate cut-points associated with positive screens, the optimal timing for screening and the acceptability of depression screening in obstetrical settings. Lastly, we explore how to manage patients who screen positive for depression and treatment options for women with PPD. PMID:19661761

Sit, Dorothy K.; Wisner, Katherine L.

2009-01-01

118

The role and clinical significance of subsyndromal depressive symptoms (SSD) in unipolar major depressive disorder  

Microsoft Academic Search

Analyses conducted in 10?526 community respondents investigated by the NIMH Epidemiological Catchment Area (ECA) Program, revealed the 1-month point prevalence of depressive symptoms and disorders in the general population, at the first ECA interview (Wave 1) to be 10%, as follows: 2.3% major depressive disorder (MDD); 2.3% dysthymic disorder (DD); 1.5% minor depressive disorder (MinD); and 3.9% subsyndromal depressive symptoms

Lewis L Judd; Hagop S Akiskal; Martin P Paulus

1997-01-01

119

Synchrotron x-ray visualisation of ice formation in insects during lethal and non-lethal freezing.  

PubMed

Although the biochemical correlates of freeze tolerance in insects are becoming well-known, the process of ice formation in vivo is subject to speculation. We used synchrotron x-rays to directly visualise real-time ice formation at 3.3 Hz in intact insects. We observed freezing in diapausing 3(rd) instar larvae of Chymomyza amoena (Diptera: Drosophilidae), which survive freezing if it occurs above -14 degrees C, and non-diapausing 3(rd) instar larvae of C. amoena and Drosophila melanogaster (Diptera: Drosophilidae), neither of which survive freezing. Freezing was readily observed in all larvae, and on one occasion the gut was seen to freeze separately from the haemocoel. There were no apparent qualitative differences in ice formation between freeze tolerant and non-freeze tolerant larvae. The time to complete freezing was positively related to temperature of nucleation (supercooling point, SCP), and SCP declined with decreasing body size, although this relationship was less strong in diapausing C. amoena. Nucleation generally occurred at a contact point with the thermocouple or chamber wall in non-diapausing larvae, but at random in diapausing larvae, suggesting that the latter have some control over ice nucleation. There were no apparent differences between freeze tolerant and non-freeze tolerant larvae in tracheal displacement or distension of the body during freezing, although there was markedly more distension in D. melanogaster than in C. amoena regardless of diapause state. We conclude that although control of ice nucleation appears to be important in freeze tolerant individuals, the physical ice formation process itself does not differ among larvae that can and cannot survive freezing. This suggests that a focus on cellular and biochemical mechanisms is appropriate and may reveal the primary adaptations allowing freeze tolerance in insects. PMID:20011523

Sinclair, Brent J; Gibbs, Allen G; Lee, Wah-Keat; Rajamohan, Arun; Roberts, Stephen P; Socha, John J

2009-01-01

120

Understanding Depression (For Parents)  

MedlinePLUS

... Word! Depression Bipolar Disorder Talking to Parents About Depression Stress & Coping Center Seasonal Affective Disorder Going to a Therapist Finding Low-Cost Mental Health Care 5 Ways to Fight Depression Posttraumatic Stress Disorder Cutting Death and Grief Depression ...

121

Freeze-fracture for scanning electron microscopy.  

PubMed

Two different freeze-fracture methods are explored for preparation of biological material for scanning electron microscopy. In the simpler method the tissues are first fixed and dehydrated. They are then frozen and fractured, and after thawing, critical-point dried. This method has already been used in a number of studies of animal tissues (heart, liver, kidney). It is applied here to the examination of plant material (leaf mesophyll cells). In the second method tissues, or cells, are first infiltrated with cryoprotectant (dimethylsulphoxide) then frozen and fractured, and not fixed until after thawing. The fixed tissues are finally dehydrated and critical-point dried. This method also has previously been used in the study of animal tissues, and is applied here to carrot protoplasts, chicken erythrocytes, and leaf mesophyll cells. PMID:599555

Haggis, G H; Phipps-Todd, B

1977-11-01

122

Postpartum Depression  

MedlinePLUS

What are the postpartum blues? About 2–3 days after childbirth, some women begin to feel depressed, anxious, and upset. They may feel angry with ... a baby These feelings, often called the postpartum blues , may come and go in the first few ...

123

Non-Toxic, Low-Freezing, Drop-In Replacement Heat Transfer Fluids  

NASA Technical Reports Server (NTRS)

A non-toxic, non-flammable, low-freezing heat transfer fluid is being developed for drop-in replacement within current and future heat transfer loops currently using water or alcohol-based coolants. Numerous water-soluble compounds were down-selected and screened for toxicological, physical, chemical, compatibility, thermodynamic, and heat transfer properties. Two fluids were developed, one with a freezing point near 0 C, and one with a suppressed freezing point. Both fluids contain an additive package to improve material compatibility and microbial resistance. The optimized sub-zero solution had a freezing point of 30 C, and a freezing volume expansion of 10-percent of water. The toxicity of the solutions was experimentally determined as LD(50) greater than 5g/kg. The solutions were found to produce minimal corrosion with materials identified by NASA as potentially existing in secondary cooling loops. Thermal/hydrodynamic performance exceeded that of glycol-based fluids with comparable freezing points for temperatures Tf greater than 20 C. The additive package was demonstrated as a buffering agent to compensate for CO2 absorption, and to prevent microbial growth. The optimized solutions were determined to have physically/chemically stable shelf lives for freeze/thaw cycles and longterm test loop tests.

Cutbirth, J. Michael

2012-01-01

124

Temperature and flow measurements on near-freezing aviation fuels in a wing-tank model  

NASA Technical Reports Server (NTRS)

Freezing behavior, pumpability, and temperature profiles for aviation turbine fuels were measured in a 190-liter tank chilled to simulate internal temperature gradients encountered in commercial airplane wing tanks. When the bulk of the fuel was above the specification freezing point, pumpout of the fuel removed all fuel except a layer adhering to the bottom chilled surfaces, and the unpumpable fraction depended on the fuel temperature near these surfaces. When the bulk of the fuel was at or below the freezing point, pumpout ceased when solids blocked the pump inlet, and the unpumpable fraction depended on the overall average temperature.

Friedman, R.; Stockemer, F. J.

1980-01-01

125

Regulation of Supercooling and Nucleation in a Freeze Intolerant Beetle (Tenebrio molitor)  

Microsoft Academic Search

The mealworm beetle, Tenebrio m&or (Tenebrionidae, Coleoptera), is a freeze-susceptible species that does not survive cooling to below the supercooling point (i.e., tissue freezing) in any stage of development. Most insects of a given age and developmental stage exhibit a relatively narrow range of supercooling point (SCP) values. However, Tenebriu larvae reared at 24°C on dry wheat bran displayed a

SEAN L. JOHNSTON; RICHARD E. LEE

1990-01-01

126

Towards a scientific taxonomy of depression  

PubMed Central

Many concepts have been introduced into the classification of depression, including manic-depressive/bipolar disorder depression, etc. Kraepelin's original concept of manic-depressive disorder has evolved into the concept of polarity, and bipolar and unipolar disorders. Psychiatric classification is characterized by an inflation of the diagnostic categories, including subtypes of depression. This rapid multiplier effect is primarily descriptive, and there is a need to rethink, in a pragmatic fashion, the classification system, in order to develop one that is likely to be of utility and which has a scientific basis. Is the time now right to ask whether there are essential conditions relevant to depression? I think that it is, and here I will introduce the notion with two such conditions. The first is early life stress disorder, and the second vascular depression. These conditions have reached a point where the data supports them as distinct entities. In this paper, the rationale for this is discussed. PMID:18979943

K. Ranga, Rama Krishnan

127

Karen Johnson Freeze Fellowship Fund  

Microsoft Academic Search

The Karen Johnson Freeze Fellowship Fund is an initiative of the Foundation for the History of Technology (SHT) and the Society for the History of Technology (SHOT) to encourage research in the field of history of technology in Central, Southeastern, and Eastern Europe. The fund also wants to contribute to the internatio- nal dissemination of research results. The Karen Johnson

J. W. A. Korsten

128

Poverty, Material Hardship and Depression  

PubMed Central

Objective Mental health disorders are of great social, economic, and policy concern. A higher incidence of major depressive disorder has been reported among those living in or near poverty. Our study examines the extent to which the relationship between income and depression is mediated by measures of material hardship. Methods We use measures of depression at two points in time from the longitudinal Fragile Families Survey to better discern the causal direction of the relationship between income poverty, hardship, and depression. More specifically, we use conditional logistic fixed-effect models that control for time-invariant unmeasured heterogeneity in the sample. Results We found a strong relationship between hardships and depression. The most prominent hardships were problems paying bills and phone turned off. We also found that hardship helped mediate much, though not all, of the link between poverty and depression in the conditional fixed effect logistic regression models. Conclusion Our policy simulations suggest that public health efforts to reduce depression may be enhanced from efforts that focus on specific forms of material hardship.

Heflin, Colleen M.; Iceland, John

2014-01-01

129

Hopelessness Depression in Depressed Inpatient Adolescents  

Microsoft Academic Search

The hopelessness theory of depression hypothesizes the existence of a hopelessness subtype of depression, characterized by its specific cause, symptoms, course, therapy, and prevention. Data from depressed inpatient adolescents (N = 160) were used to evaluate (a) the relation between hopelessness and the hypothesized symptoms of hopelessness depression; and (b) the latent structure of the relation between hopelessness and the

Mark A. Whisman; Aureen Pinto

1997-01-01

130

Insect Cold-Hardiness: To Freeze or Not to Freeze Richard E. Lee, Jr.  

E-print Network

. The capacity to cold-harden is required for overwintering to survive long-term or short-term exposure to lowInsect Cold-Hardiness: To Freeze or Not to Freeze Richard E. Lee, Jr. BioScience, Vol. 39, No. 5 #12;Insect Cold-hardiness: To Freeze or Not to Freeze How insects survive low temperatures

Lee Jr., Richard E.

131

Crystal structures and freezing of dipolar fluids  

E-print Network

We investigate the crystal structure of classical systems of spherical particles with an embedded point dipole at T=0. The ferroelectric ground state energy is calculated using generalizations of the Ewald summation technique. Due to the reduced symmetry compared to the nonpolar case the crystals are never strictly cubic. For the Stockmayer (i.e., Lennard-Jones plus dipolar) interaction three phases are found upon increasing the dipole moment: hexagonal, body-centered orthorhombic, and body-centered tetragonal. An even richer phase diagram arises for dipolar soft spheres with a purely repulsive inverse power law potential $\\sim r^{-n}$. A crossover between qualitatively different sequences of phases occurs near the exponent $n=12$. The results are applicable to electro- and magnetorheological fluids. In addition to the exact ground state analysis we study freezing of the Stockmayer fluid by density-functional theory.

B. Groh; S. Dietrich

2000-10-21

132

Crystal structures and freezing of dipolar fluids.  

PubMed

We investigate the crystal structure of classical systems of spherical particles with an embedded point dipole at T=0. The ferroelectric ground state energy is calculated using generalizations of the Ewald summation technique. Due to the reduced symmetry compared to the nonpolar case the crystals are never strictly cubic. For the Stockmayer (i.e., Lennard-Jones plus dipolar) interaction three phases are found upon increasing the dipole moment: hexagonal, body-centered orthorhombic, and body-centered tetragonal. An even richer phase diagram arises for dipolar soft spheres with a purely repulsive inverse power law potential approximately r(-n). A crossover between qualitatively different sequences of phases occurs near the exponent n=12. The results are applicable to electro- and magnetorheological fluids. In addition to the exact ground state analysis we study freezing of the Stockmayer fluid by density-functional theory. PMID:11308482

Groh, B; Dietrich, S

2001-02-01

133

Heat pump with freeze-up prevention  

DOEpatents

What is disclosed is a heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating the fluid in heat exchange relationship with a refrigerant fluid; at least two refrigerant heat exchangers, one for effecting heat exchange with the fluid and a second for effecting heat exchange between refrigerant and a heat exchange fluid and the ambient air; a compressor for efficiently compressing the refrigerant; at least one throttling valve for throttling liquid refrigerant; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circulating device and heat exchange fluid circuit for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and direction of flow of the refrigerant therethrough for selecting a particular mode of operation. The heat exchange fluid prevents freeze up of the second heat exchanger by keeping the temperature above the dew point; and, optionally, provides heat for efficient operation.

Ecker, Amir L. (Dallas, TX)

1981-01-01

134

Nonpsychotic Postpartum Depression Among Adolescent Mothers  

Microsoft Academic Search

This study examined the extent to which childbearing increases vulnerability to clinical depression and depressive symptomatology among primiparous adolescent girls (ages 14 to 18). Childbearing Ss (n = 128) were assessed during pregnancy, 6 weeks postpartum, and 1 year postpartum. Matched nonchildbearing Ss (n = 114) were assessed at corresponding time points. Six weeks postpartum, 6% of the childbearing adolescents

Beth R. Troutman; Carolyn E. Cutrona

1990-01-01

135

Executive functioning moderates the relationship between motivation and adolescent depressive symptoms  

PubMed Central

We investigated the association between adolescent depressive symptoms and components of executive functioning (EF), including planning (Tower of London), set-shifting (Wisconsin Card Sorting Task), and inhibition (Stop Signal Task) in a community sample of 12–14 year olds. Further, EF was tested as a moderator of motivation (as operationalized by revised Reinforcement Sensitivity Theory) effects on depressive symptoms. Results suggested that planning ability was associated with depressive symptoms. Furthermore, planning ability moderated the relationship between motivation (fight-flight- freeze system; FFFS) and depressive symptoms, such that among adolescents with poor planning ability the FFFS positively predicted depressive symptoms, but among adolescents with strong planning ability the FFFS negatively predicts depressive symptoms. Neither set-shifting nor inhibition was associated with depressive symptoms. Findings highlight the need to consider multiple components of EF and to integrate motivational and executive dysfunction models to the study of depression. PMID:23105161

Vergara-Lopez, Chrystal; Lopez-Vergara, Hector I.; Colder, Craig R.

2012-01-01

136

Freeze Technology for Nuclear Applications - 13590  

SciTech Connect

Freezing of soil materials is a complicated process of a number of physical processes: - freezing of pore water in a thermal gradient, - cryogenic suction causing water migration and - ice formation expanding pores inducing frost heave. Structural changes due to increase of effective stress during freezing also take place. The over consolidation gives a powerful dewatering/drying effect and the freeze process causes separation of contaminates. Artificial ground freezing (AGF is a well established technique first practiced in south Wales, as early as 1862. AGF is mostly used to stabilize tunnels and excavations. During the last ten years underwater applications of freeze technologies based on the AGF have been explored in Sweden. The technology can, and has been, used in many different steps in a remediation action. Freeze Sampling where undisturbed samples are removed in both soft and hard sediment/sludge, Freeze Dredging; retrieval of sediment with good precision and minimal redistribution, and Freeze Drying; volume reduction of contaminated sludge/sediment. The application of these technologies in a nuclear or radioactive environment provides several advantages. Sampling by freezing gives for example an advantage of an undisturbed sample taken at a specified depth, salvaging objects by freezing or removal of sludges is other applications of this, for the nuclear industry, novel technology. (authors)

Rostmark, Susanne C.; Knutsson, Sven [Lulea University of Technology (Sweden)] [Lulea University of Technology (Sweden); Lindberg, Maria [Studsvik Nuclear AB, 611 82 Nykoeping (Sweden)] [Studsvik Nuclear AB, 611 82 Nykoeping (Sweden)

2013-07-01

137

Depression: What We Know.  

ERIC Educational Resources Information Center

This booklet is concerned with the area of clinical depression. Questions about clinical depression are briefly answered in an overview section and are examined in greater detail in the five chapters that follow. In chapter 1, depression is defined and various types of depression are identified. The origins of depression are explored in the second…

Lobel, Brana; Hirschfeld, Robert M. A.

138

Directional freezing of reproductive cells and organs.  

PubMed

Directional freezing is based on a simple thermodynamic principle where ice crystals are precisely controlled through the sample by regulating the velocity of the sample movement through the predetermined temperature gradient. Directional freezing permits a precise and uniform cooling rate in both small and large volume samples. Directional freezing was used for slow and rapid freezing, as well as for vitrification of oocytes and embryos using the minimum drop size technique. Sperm samples from a wide range of domestic and wild animals were successfully cryopreserved using the directional freezing method. The method enabled, for the first time, successful freezing of a whole ovary and freeze-drying of mammalian cells followed by thawing and transplantation and rehydration, respectively. PMID:22827370

Arav, A; Natan, D

2012-08-01

139

Freeze chromatography method and apparatus  

DOEpatents

A freeze chromatography method and apparatus are provided which enable separation of the solutes contained in a sample. The apparatus includes an annular column construction comprising cylindrical inner and outer surfaces defining an annular passage therebetween. One of the surfaces is heated and the other cooled while passing an eluent through the annular passageway so that the eluent in contact with the cooled surface freezes and forms a frozen eluent layer thereon. A mixture of solutes dissolved in eluent is passed through the annular passageway in contact with the frozen layer so that the sample solutes in the mixture will tend to migrate either toward or away the frozen layer. The rate at which the mixture flows through the annular passageway is controlled so that the distribution of the sample solutes approaches that at equilibrium and thus a separation between the sample solutes occurs. 3 figs.

Scott, C.D.

1987-04-16

140

Control of glycerol production by rainbow smelt ( Osmerus mordax) to provide freeze resistance and allow foraging at low winter temperatures  

Microsoft Academic Search

The rainbow smelt (Osmerus mordax) is a small anadromous fish that actively feeds under the ice at temperatures as low as the freeze point of seawater. Freezing is avoided through the production of both non-colligative antifreeze protein (AFP) and glycerol that acts in a colligative manner. Glycerol is constantly lost across the gills and skin, thus glycerol production must continue

William R. Driedzic; K. Vanya Ewart

2004-01-01

141

Breast Cancer and Depression  

MedlinePLUS Videos and Cool Tools

... the lower right-hand corner of the player. Breast Cancer and Depression HealthDay October 28, 2014 Related MedlinePlus Pages Breast Cancer Depression Women's Health Transcript Depression is a disabling ...

142

Depression and Alzheimer's Disease  

MedlinePLUS

... right-hand corner of the player. Depression and Alzheimer's Disease HealthDay January 15, 2015 Related MedlinePlus Pages Alzheimer's Disease Depression Transcript Depression and anxiety are common in ...

143

Alcoholism & depression.  

PubMed

One out of 2 Americans report drinking on a routine basis, making the excessive consumption of alcohol the third leading cause of preventable death in America (). Alcoholism and depression are common comorbidities that home healthcare professionals frequently encounter. To achieve the best patient outcomes, alcoholism should be addressed initially. Although all age groups are at risk, alcoholism and depression occur in more than 8 percent of older adults. Prevention through identifying alcohol use early in adolescence is vital to reduce the likelihood of alcohol dependence. This article provides an overview of the long-term effects of alcohol abuse, including alcoholic cirrhosis and hepatic encephalopathy. The diagnostic criteria for substance dependence and ideas for nonthreatening screening questions to use with patients who are adolescent or older are discussed. While providing patient care, home healthcare nurses share the patient's intimate home environment. This environment is perceived as a safe haven by the patient and home care nurses can take advantage of counseling and treatment opportunities in this nonthreatening environment. PMID:23026991

Hall, Mellisa

2012-10-01

144

[Depressive symptoms and sexuality].  

PubMed

The mutually reinforcing dyad of depressive symptoms and erectile dysfunction is scientifically established. The cure of depression improves sexual dysfunction (SD) and the treatment of SD induces improvement of depression. Most of anti-depressants induce negative sexual side effects that lead to non-compliance of these treatments. The knowledge of interrelation between depression, anti-depressants and sexuality is of great importance in clinical practice. PMID:25148948

Porto, Robert

2014-10-01

145

Altered BDNF and Dopamine Levels In Depression  

NSDL National Science Digital Library

Doctor Abraham Zangen point out that dopamine and BDNF levels in the nucleus accumbens and hippocampus of depressed patients are different. Treatment with antidepressants or ECT can impact these differences.

2009-12-26

146

Postpartum Depression Action Plan  

MedlinePLUS

MENU Return to Web version Postpartum Depression | Postpartum Depression Action Plan Patient __________________________ Physician/NP/PA __________________ Clinic ____________________________ Phone Number ____________________ Choose one area and add other ...

147

The postpartum depression screening scale: is it valid to screen for antenatal depression?  

Microsoft Academic Search

The purpose of the study was to analyse for the first time the validity of a slightly modified version of the Portuguese Postpartum\\u000a Depression Screening Scale (PDSS), to be used as a screening instrument for antenatal depression. Specifically, the aims were\\u000a to analyse its psychometric properties, to determine PDSS cutoff points and associated conditional probabilities to screen\\u000a for depression according

Ana Telma Pereira; Sandra C. Bos; Mariana Marques; Berta R. Maia; Maria João Soares; José Valente; Ana Allen Gomes; António Macedo; Maria Helena Pinto de Azevedo

2011-01-01

148

Characteristics of sugar surfactants in stabilizing proteins during freeze-thawing and freeze-drying.  

PubMed

Sugar surfactants with different alkyl chain lengths and sugar head groups were compared for their protein-stabilizing effect during freeze-thawing and freeze-drying. Six enzymes, different in terms of tolerance against inactivation because of freeze-thawing and freeze-drying, were used as model proteins. The enzyme activities that remained after freeze-thawing and freeze-drying in the presence of a sugar surfactant were measured for different types and concentrations of sugar surfactants. Sugar surfactants stabilized all of the tested enzymes both during freeze-thawing and freeze-drying, and a one or two order higher amount of added sugar surfactant was required for achieving protein stabilization during freeze-drying than for the cryoprotection. The comprehensive comparison showed that the C10-C12 esters of sucrose or trehalose were the most effective through the freeze-drying process: the remaining enzyme activities after freeze-thawing and freeze-drying increased at the sugar ester concentrations of 1-10 and 10-100 ?M, respectively, and increased to a greater extent than for the other surfactants at higher concentrations. Results also indicate that, when a decent amount of sugar was also added, the protein-stabilizing effect of a small amount of sugar ester through the freeze-drying process could be enhanced. PMID:24797557

Imamura, Koreyoshi; Murai, Katsuyuki; Korehisa, Tamayo; Shimizu, Noriyuki; Yamahira, Ryo; Matsuura, Tsutashi; Tada, Hiroko; Imanaka, Hiroyuki; Ishida, Naoyuki; Nakanishi, Kazuhiro

2014-06-01

149

Freeze-drying of mammalian sperm.  

PubMed

Long-term preservation of mammalian sperm at suprazero temperatures is desired to save storage and space costs as well as to facilitate transport of preserved samples. This can be accomplished by the freeze-drying of sperm samples. Although freeze-drying results in immotile and membrane-compromised sperm, intracytoplasmic sperm injection (ICSI) can be used to introduce such an immotile sperm into an oocyte and thus start the fertilization process. So far, it has been shown that improved freeze-drying protocols preserve chromosomal integrity and oocyte-activating factor(s) at 4 °C for several years and at ambient temperature for approximately 1 month, which permits shipping freeze-dried samples at ambient temperature. This chapter concisely reviews freeze-drying of mammalian sperm first and then presents a simple freeze-drying protocol. PMID:25428025

Keskintepe, Levent; Eroglu, Ali

2015-01-01

150

Development and design of sludge freezing beds  

SciTech Connect

The purpose of this study was to develop design criteria for a new sludge dewatering unit operation called a sludge freezing bed. This bed uses natural freeze-thaw to condition the sludge for dewatering. The total depth of sludge which can be frozen, thawed and dewatered by this process in a year is the main criterion needed for design. The essential features of a freezing bed which would optimize natural freeze-thaw were identified through a literature review and site visits. Several laboratory tests were conducted to assess the dewaterability of freeze-thaw conditioned sludge at various depths. Water treatment plant sludge and both anaerobically and aerobically digested wastewater sludges were used in these tests. Mathematical models for predicting the design depth were developed and validated with data from other sludge freezing operations. Values for the input parameters to the models were obtained from the literature or from laboratory and pilot-scale experiments.

Martel, C.J.

1987-01-01

151

Freeze-drying of spermatozoa.  

PubMed

Bull semen was diluted to a concentration of 2 X 10(8) cells/ml, cooled to 5 degrees C in 5 h, frozen in 0.025 ml spheres on the surface of solid carbon dioxide, and stored in liquid nitrogen. 50% by volume of the diluent was 325 m0sm Tes:N-tris (hydroxymethyl) methyl-2-amino ethane sulfonic acid titrated to pH 7.2 with 325 m0sm Tris:tris (hydroxymethyl) amino methane. The diluent also contained 30% by volume isotonic sodium citrate and 20% by volume egg yolk. The frozen spermatozoa were freeze-dried in 400 mg quantities in test tubes at -50 degrees C with a condenser at -196 degrees C. Moisture content was determined by weighing the individual samples before and after freeze-drying. Drying the samples for several days at 20 degrees C removed 868 mg from each gram of frozen material and this was considered the zero moisture level. Samples were stored at 20 degrees C or -196 degrees C after freeze-drying. The freezer-dried samples were rehydrated by flooding with five times their original volume of isotonic sodium citrate. Tests of the recovered spermatozoa included percentage motile cells, acrosome damage, enzyme release, protein denaturation, hypotonic swelling and fertility testing. Sperm motility decreased with dryness until it reached zero at 3% moisture. Acrosome morphology and enzyme release appeared normal down to 1% moisture. Preliminary results showed some fertility at all levels of dryness with -196 degrees C storage, and fertility at less than 1% moisture with 20 degrees C storage. Additional fertility testing is underway. PMID:1030432

Larson, E V; Graham, E F

1976-10-01

152

Freezing of stallion epididymal sperm.  

PubMed

Inseminations with frozen-thawed epididymal sperm have resulted in low-pregnancy rates of mares. If fertility of epididymal sperm could be improved, it would help to preserve genetic material from stallions that have suffered severe injuries, been castrated or have died. The aim of the present study was to investigate the effect of different extenders and pre-freezing addition of capacitation media on freezability of epididymal sperm and on storage at 5 degrees C for 24h. In experiment 1, epididymal sperm samples were diluted and subsequently frozen with three different extenders: Botu-Crio, EDTA-Lactose and INRA-82. Motility analysis using computer assisted sperm analyzer (CASA) demonstrated better motility for sperm in Botu-Crio than in the other extenders; EDTA-Lactose yielded better motility than INRA-82 on most evaluated parameters. There was no difference in membrane integrity among the studied extenders. From 18 inseminated mares, 12 (66%) were pregnant 15 days after AI with frozen-thawed epididymal sperm showing that Botu-Crio was able to maintain the fertility potential. In experiment 2, the effect of incubation of epididymal sperm before freezing in three capacitation media (Fert Talp, Sperm Talp, Talp+Progesterone), seminal plasma, or control was tested. Based on post-thaw motility evaluation by CASA, samples incubated in Sperm Talp showed better motility values. There were no differences in plasma or acrosomal membranes or in mitochondrial potential among groups. We concluded that Botu-Crio was better than the other extenders in the ability to preserve epididymal sperm and that pre-freeze addition of Sperm Talp was also beneficial. PMID:18556154

Papa, F O; Melo, C M; Fioratti, E G; Dell'aqua, J A; Zahn, F S; Alvarenga, M A

2008-09-01

153

Predicting freezing for some repulsive potentials.  

PubMed

We propose a simple method to approximately predict the freezing (fluid-solid) phase transition in systems of particles interacting via purely repulsive potentials. The method is based on the striking universality of the freezing curve for the model Yukawa and inverse-power-law interactions. This method is applied to draw an exemplary phase diagram of complex plasmas. We suggest that it can also be used to locate freezing transition in other substances with similar properties of interaction. PMID:20366260

Khrapak, S A; Morfill, G E

2009-12-18

154

Spin Probe ESR Signature of Freezing in Water: Is it Global or Local?  

E-print Network

First systematic spin probe ESR study of water freezing has been conducted using TEMPOL and TEMPO as the probes. The spin probe signature of the water freezing has been described in terms of the collapse of narrow triplet spectrum into a single broad line. This spin probe signature of freezing has been observed at an anomalously low temperature when a milimoler solution of TEMPOL is slowly cooled from room temperature. A systematic observation has revealed a spin probe concentration dependence of these freezing and respective melting points. These results can be explained in terms of localization of spin probe and liquid water, most probably in the interstices of ice grains, in an ice matrix. The lowering of spin probe freezing point, along with the secondary evidences, like spin probe concentration dependence of peak-to-peak width in frozen limit signal, indicates a possible size dependence of these localizations/entrapments with spin probe concentration. A weak concentration dependence of spin probe assisted freezing and melting points, which has been observed for TEMPO in comparison to TEMPOL, indicates different natures of interactions with water of these two probes. This view is also supported by the relaxation behavior of the two probes.

Debamalya Banerjee; S. V. Bhat

2008-10-26

155

Egg freezing: a breakthrough for reproductive autonomy?  

PubMed

This article describes the relatively new technology of freezing human eggs and examines whether egg freezing, specifically when it is used by healthy women as 'insurance' against age-related infertility, is a legitimate exercise of reproductive autonomy. Although egg freezing has the potential to expand women's reproductive options and thus may represent a breakthrough for reproductive autonomy, I argue that without adequate information about likely outcomes and risks, women may be choosing to freeze their eggs in a commercially exploitative context, thus undermining rather than expanding reproductive autonomy. PMID:18945249

Harwood, Karey

2009-01-01

156

Freezing resistance of antifreeze-deficient larval Antarctic fish.  

PubMed

Antarctic notothenioids, along with many other polar marine fishes, have evolved biological antifreeze proteins (AFPs) to survive in their icy environments. The larvae of Antarctic notothenioid fish hatch into the same frigid environment inhabited by the adults, suggesting that they must also be protected by sufficient AFPs, but this has never been verified. We have determined the contribution of AFPs to the freezing resistance of the larvae of three species: Gymnodraco acuticeps, Pagothenia borchgrevinki and Pleuragramma antarcticum. Of the three, only P. borchgrevinki larvae are protected by high, adult levels of AFPs. Hatchling G. acuticeps and P. antarcticum have drastically inadequate AFP concentrations to avoid freezing at the ambient seawater temperature (-1.91 degrees C). We raised G. acuticeps larvae and measured the AFP levels in their blood for approximately 5 months post hatching. Larval serum freezing point was -1.34+/-0.04 degrees C at the time of hatch; it began to decrease only after 30 days post hatch (d.p.h.), and finally reached the adult value (-2.61+/-0.03 degrees C) by 147 d.p.h. Additionally, AFP concentrations in their intestinal fluids were very low at hatching, and did not increase with age throughout a sampling period of 84 d.p.h. Surviving in a freezing environment without adequate AFP protection suggests that other mechanisms of larval freezing resistance exist. Accordingly, we found that G. acuticeps hatchlings survived to -3.6+/-0.1 degrees C while in contact with external ice, but only survived to -1.5+/-0.0 degrees C when ice was artificially introduced into their tissues. P. antarcticum larvae were similarly resistant to organismal freezing. The gills of all three species were found to be underdeveloped at the time of hatch, minimizing the risk of ice introduction through these delicate structures. Thus, an intact integument, underdeveloped gill structures and other physical barriers to ice propagation may contribute significantly to the freezing resistance and survival of these larval fishes in the icy conditions of the Southern Ocean. PMID:16424091

Cziko, Paul A; Evans, Clive W; Cheng, Chi-Hing C; DeVries, Arthur L

2006-02-01

157

Cognitive Biases and Depression  

Microsoft Academic Search

Compared symptomatically depressed, clinically remitted, and normal controls using cognitive measures designed to be traitlike and statelike in cross-sectional and longitudinal designs, respectively. Remitted depressives and normal subjects did not differ in their attributional biases, endorsement of dysfunctional attitudes, or interpretation of schema-relevant ambiguous events, but both groups differed from symptomatic depressives. Depressive episodes thus affect cognition, but cognitions measured

Kevin B. Dohr; A. John Rush; Ira H. Bernstein

1989-01-01

158

The Great Depression  

NSDL National Science Digital Library

Students will understand the personal impact of the depression on the lives of Americans. We will follow Utah\\'s Social Studies core curriculum Standard 6: Students will understand how the Great Depression and the New Deal affected the United States. Objective 1 Investigate the impact of the Great Depression on the United States. * Analyze the major causes of the Great Depression. ...

Randyandamber

2007-11-30

159

Food freezing with simultaneous surface dehydration: approximate prediction of freezing time  

Microsoft Academic Search

Freezing of unpackaged foods induces mass transfer in the form of surface ice sublimation, which in turn modifies heat transfer conditions. At present there are no simplified methods for predicting freezing times when surface dehydration occurs. This paper uses a previously developed model for the simulation of simultaneous heat and mass transfer during food freezing and storage to generate a

Laura A. Campañone; Viviana O. Salvadori; Rodolfo H. Mascheroni

2005-01-01

160

Learning and memory impairments in a neuroendocrine mouse model of anxiety/depression  

PubMed Central

Cognitive disturbances are often reported as serious incapacitating symptoms by patients suffering from major depressive disorders (MDDs). Such deficits have been observed in various animal models based on environmental stress. Here, we performed a complete characterization of cognitive functions in a neuroendocrine mouse model of depression based on a chronic (4 weeks) corticosterone administration (CORT). Cognitive performances were assessed using behavioral tests measuring episodic (novel object recognition test, NORT), associative (one-trial contextual fear conditioning, CFC), and visuo-spatial (Morris water maze, MWM; Barnes maze, BM) learning/memory. Altered emotional phenotype after chronic corticosterone treatment was confirmed in mice using tests predictive of anxiety or depression-related behaviors. In the NORT, CORT-treated mice showed a decrease in time exploring the novel object during the test session and a lower discrimination index compared to control mice, characteristic of recognition memory impairment. Associative memory was also impaired, as observed with a decrease in freezing duration in CORT-treated mice in the CFC, thus pointing out the cognitive alterations in this model. In the MWM and in the BM, spatial learning performance but also short-term spatial memory were altered in CORT-treated mice. In the MWM, unlike control animals, CORT-treated animals failed to learn a new location during the reversal phase, suggesting a loss of cognitive flexibility. Finally, in the BM, the lack of preference for the target quadrant during the recall probe trial in animals receiving corticosterone regimen demonstrates that long-term retention was also affected in this paradigm. Taken together, our results highlight that CORT-induced anxio-depressive-like phenotype is associated with a cognitive deficit affecting all aspects of memory tested. PMID:24822041

Darcet, Flavie; Mendez-David, Indira; Tritschler, Laurent; Gardier, Alain M.; Guilloux, Jean-Philippe; David, Denis J.

2014-01-01

161

Learning and memory impairments in a neuroendocrine mouse model of anxiety/depression.  

PubMed

Cognitive disturbances are often reported as serious incapacitating symptoms by patients suffering from major depressive disorders (MDDs). Such deficits have been observed in various animal models based on environmental stress. Here, we performed a complete characterization of cognitive functions in a neuroendocrine mouse model of depression based on a chronic (4 weeks) corticosterone administration (CORT). Cognitive performances were assessed using behavioral tests measuring episodic (novel object recognition test, NORT), associative (one-trial contextual fear conditioning, CFC), and visuo-spatial (Morris water maze, MWM; Barnes maze, BM) learning/memory. Altered emotional phenotype after chronic corticosterone treatment was confirmed in mice using tests predictive of anxiety or depression-related behaviors. In the NORT, CORT-treated mice showed a decrease in time exploring the novel object during the test session and a lower discrimination index compared to control mice, characteristic of recognition memory impairment. Associative memory was also impaired, as observed with a decrease in freezing duration in CORT-treated mice in the CFC, thus pointing out the cognitive alterations in this model. In the MWM and in the BM, spatial learning performance but also short-term spatial memory were altered in CORT-treated mice. In the MWM, unlike control animals, CORT-treated animals failed to learn a new location during the reversal phase, suggesting a loss of cognitive flexibility. Finally, in the BM, the lack of preference for the target quadrant during the recall probe trial in animals receiving corticosterone regimen demonstrates that long-term retention was also affected in this paradigm. Taken together, our results highlight that CORT-induced anxio-depressive-like phenotype is associated with a cognitive deficit affecting all aspects of memory tested. PMID:24822041

Darcet, Flavie; Mendez-David, Indira; Tritschler, Laurent; Gardier, Alain M; Guilloux, Jean-Philippe; David, Denis J

2014-01-01

162

Depression in Cognitive Impairment  

PubMed Central

Depression and cognitive disorders, including dementia and mild cognitive impairment, are common in the elderly. Depression is also a common feature of cognitive impairment although the symptoms of depression in cognitive impairment differ from depression without cognitive impairment. Pre-morbid depression approximately doubles the risk of subsequent dementia. There are two predominant, though not mutually exclusive, constructs linking pre-morbid depression to subsequent cognitive impairment: Alzheimer’s pathology and the vascular depression hypothesis. When evaluating a patient with depression and cognitive impairment, it is important to obtain caregiver input and to evaluate for alternative etiologies for depressive symptoms such as delirium. We recommend a sequential approach to the treatment of depression in dementia patients: (1) a period of watchful waiting for milder symptoms, (2) psychosocial treatment program, (3) a medication trial for more severe symptoms or failure of psychosocial interventions, and (4) possible ECT for refractory symptoms. PMID:23933974

Pellegrino, Laurel D.; Lyketsos, Constantine G.; Marano, Christopher M.

2014-01-01

163

Controlled freezing of nonideal solutions with application to cryosurgical processes.  

PubMed

Success of a cryosurgical procedure, i.e., maximal cell destruction, requires that the cooling rate be controlled during the freezing process. Standard cryosurgical devices are not usually designed to perform the required controlled process. In this study, a new cryosurgical device was developed which facilitates the achievement of a specified cooling rate during freezing by accurately controlling the probe temperature variation with time. The new device has been experimentally tested by applying it to an aqueous solution of mashed potatoes. The temperature field in the freezing medium, whose thermal properties are similar to those of biological tissue, was measured. The cryoprobe temperature was controlled according to a desired time varying profile which was assumed to maximize necrosis. The tracking accuracy and the stability of the closed loop control system were investigated. It was found that for most of the time the tracking accuracy was excellent and the error between the measured probe temperature and the desired set point is within +/- 0.4 degrees C. However, noticeable deviations from the set point occurred due to the supercooling phenomenon or due to the instability of the liquid nitrogen boiling regime in the cryoprobe. The experimental results were compared to those obtained by a finite elements program and very good agreement was obtained. The deviation between the two data sets seems to be mainly due to errors in positioning of the thermocouple junctions in the medium. PMID:1762441

Budman, H M; Dayan, J; Shitzer, A

1991-11-01

164

Neurological signs and late-life depressive symptoms in a community population: the ESPRIT Study  

E-print Network

that the causes of depression in the elderly may be different from that occurring in young adults, in that1 Neurological signs and late-life depressive symptoms in a community population: the ESPRIT Study: Neurological signs, Late-life Depression, Depressive symptoms, Old age, Neurodegenerative theory Key points

Boyer, Edmond

165

Depression and Risk of Heart Failure Among the Elderly: A Prospective Community-Based Study  

Microsoft Academic Search

Objective: Although the association between depression and the incidence of coronary heart disease has been established in many studies, the impact of depression on the incidence of heart failure has not been previously investigated. Methods: We examined the effect of depression (assessed by means of the Center for Epidemiological Studies Depression Scale (CES-D) with a cutoff point of 21) on

SETAREH A. WILLIAMS; STANISLAV V. KASL; ASEFEH HEIAT; JEROME L. ABRAMSON; HARLAN M. KRUMHOLZ; VIOLA VACCARINO

2002-01-01

166

Assessment of depression in medical patients: A systematic review of the utility of the Beck Depression Inventory-II  

PubMed Central

To perform a systematic review of the utility of the Beck Depression Inventory for detecting depression in medical settings, this article focuses on the revised version of the scale (Beck Depression Inventory-II), which was reformulated according to the DSM-IV criteria for major depression. We examined relevant investigations with the Beck Depression Inventory-II for measuring depression in medical settings to provide guidelines for practicing clinicians. Considering the inclusion and exclusion criteria seventy articles were retained. Validation studies of the Beck Depression Inventory-II, in both primary care and hospital settings, were found for clinics of cardiology, neurology, obstetrics, brain injury, nephrology, chronic pain, chronic fatigue, oncology, and infectious disease. The Beck Depression Inventory-II showed high reliability and good correlation with measures of depression and anxiety. Its threshold for detecting depression varied according to the type of patients, suggesting the need for adjusted cut-off points. The somatic and cognitive-affective dimension described the latent structure of the instrument. The Beck Depression Inventory-II can be easily adapted in most clinical conditions for detecting major depression and recommending an appropriate intervention. Although this scale represents a sound path for detecting depression in patients with medical conditions, the clinician should seek evidence for how to interpret the score before using the Beck Depression Inventory-II to make clinical decisions. PMID:24141845

Wang, Yuan-Pang; Gorenstein, Clarice

2013-01-01

167

Metabolic activity of permafrost bacteria below the freezing point  

NASA Technical Reports Server (NTRS)

Metabolic activity was measured in the laboratory at temperatures between 5 and -20 degrees C on the basis of incorporation of (14)C-labeled acetate into lipids by samples of a natural population of bacteria from Siberian permafrost (permanently frozen soil). Incorporation followed a sigmoidal pattern similar to growth curves. At all temperatures, the log phase was followed, within 200 to 350 days, by a stationary phase, which was monitored until the 550th day of activity. The minimum doubling times ranged from 1 day (5 degrees C) to 20 days (-10 degrees C) to ca. 160 days (-20 degrees C). The curves reached the stationary phase at different levels, depending on the incubation temperature. We suggest that the stationary phase, which is generally considered to be reached when the availability of nutrients becomes limiting, was brought on under our conditions by the formation of diffusion barriers in the thin layers of unfrozen water known to be present in permafrost soils, the thickness of which depends on temperature.

Rivkina, E. M.; Friedmann, E. I.; McKay, C. P.; Gilichinsky, D. A.

2000-01-01

168

Circadian rhythms, melatonin and depression.  

PubMed

The master biological clock situated in the suprachiasmatic nuclei of the anterior hypothalamus plays a vital role in orchestrating the circadian rhythms of multiple biological processes. Increasing evidence points to a role of the biological clock in the development of depression. In seasonal depression and in bipolar disorders it seems likely that the circadian system plays a vital role in the genesis of the disorder. For major unipolar depressive disorder (MDD) available data suggest a primary involvement of the circadian system but further and larger studies are necessary to conclude. Melatonin and melatonin agonists have chronobiotic effects, which mean that they can readjust the circadian system. Seasonal affective disorders and mood disturbances caused by circadian malfunction are theoretically treatable by manipulating the circadian system using chronobiotic drugs, chronotherapy or bright light therapy. In MDD, melatonin alone has no antidepressant action but novel melatoninergic compounds demonstrate antidepressant properties. Of these, the most advanced is the novel melatonin agonist agomelatine, which combines joint MT1 and MT2 agonism with 5-HT(2C) receptor antagonism. Adding a chronobiotic effect to the inhibition of 5-HT(2C) receptors may explain the rapid impact of agomelatine on depression, since studies showed that agomelatine had an early impact on sleep quality and alertness at awakening. Further studies are necessary in order to better characterize the effect of agomelatine and other novel melatoninergic drugs on the circadian system of MDD patients. In summary, antidepressants with intrinsic chronobiotic properties offer a novel approach to treatment of depression. PMID:21476953

Quera Salva, M A; Hartley, S; Barbot, F; Alvarez, J C; Lofaso, F; Guilleminault, C

2011-01-01

169

Non-equilibrium freezing behaviour of aqueous systems.  

PubMed

The tendencies to non-equilibrium freezing behaviour commonly noted in representative aqueous systems derive from bulk and surface properties according to the circumstances. Supercooling and supersaturation are limited by heterogeneous nucleation in the presence of solid impurities. Homogeneous nucleation has been observed in aqueous systems freed from interfering solids. Once initiated, crystal growth is ofter slowed and, very frequently, terminated with increasing viscosity. Nor does ice first formed always succeed in assuming its most stable crystalline form. Many of the more significant measurements on a given systeatter permitting the simultaneous representation of thermodynamic and non-equilibrium properties. The diagram incorporated equilibrium melting points, heterogeneous nucleation temperatures, homogeneous nucleation temperatures, glass transition and devitrification temperatures, recrystallization temperatures, and, where appropriate, solute solubilities and eutectic temperatures. Taken together, the findings on modle systems aid the identification of the kinetic and thermodynamic factors responsible for the freezing-thawing survival of living cells. PMID:17872

MacKenzie, A P

1977-03-29

170

Laboratory experiments on homogeneous and heterogeneous freezing  

NASA Astrophysics Data System (ADS)

The freezing temperature of the binary H_2SO_4 / H_2O solution droplets has been measured in dependence on their acid concentrations by means of acoustic levitation laboratory experiments. Pure solution droplets were analysed, in order to freeze the droplets as far as possible homogeneously. To induce heterogeneous freezing the droplets were contanimated with substances such as graphite, and the minerals kaolin and montmorillonite. The influence of these particles present in the liquid on the freezing temperature was measured. The size radii of the suspended droplets were between 0,4 - 1,1 mm and the concentration of the liquid acid solution was varied between 5 - 25 weight percent. The experiments show that the pure solution can be supercooled well below the equilibrium curve. Furthermore the presence of foreign particles within the solution increases the freezing temperature. The collected data reveal that the quality of the used particles as nuclei for freezing also depends on the particle material properties. Not only the presence of particles in the solution alone influences the freezing temperature of the droplets, but also the chemical composition and the surface charactaristics. In this contribution details of the experimental conditions are presented together with the measured freezing temperatures.

Borrmann, S.; Ettner, M.; Mitra, S. K.; Hannemann, A.; Sommer, C.; Peter, Th.

2003-04-01

171

A Phase-Field Solidification Model of Almost Pure ITS-90 Fixed Points  

NASA Astrophysics Data System (ADS)

A two-dimensional axisymmetric phase-field model of thermo-solutal solidification in freezing-point cells used for calibrating standard platinum resistance thermometers for realization and dissemination of the International Temperature Scale of 1990 is presented. The cell is essentially a graphite crucible containing an ingot of very pure metal (of order 99.9999 %). A graphite tube is inserted along the axis of the ingot to enable immersion of the thermometer in the metal. In this study, the metal is tin (freezing temperature of ). During the freezing of these cells, a steady, reproducible temperature is realized, with a defined temperature that can be used to calibrate thermometers with uncertainties mK. The model is applied to understand the effect of experimental parameters, such as initiation technique and furnace homogeneity, on the measured freezing curve. Results show that freezing curves whose behavior is consistent with the Scheil theory of solidification can be obtained with a specific furnace temperature profile, and provided that the freeze is of a long duration, the results are consistent with previous one-dimensional models and experiments. Morphological instability is observed with the inner interface initiation technique, causing the interface to adopt a cellular structure. This elevates the measured temperature, in accordance with the Gibbs-Thomson effect. In addition, the influence of initiation techniques on the solidification behavior is examined. The model indicates that an initially smooth inner mantle can `de-wet' from the thermometer well-forming agglomerated solid droplets, following recalescence, under certain conditions. This manifests as a measured temperature depression due to the Gibbs-Thomson effect, with a magnitude of to in simulations. The temperature rises to that of the stable outer mantle as freezing progresses and the droplets re-melt. It is demonstrated that the effect occurs below a critical mantle thickness. A physical explanation for the origin of the effect is offered showing that it is consistent with solid-state de-wetting phenomena. Consideration is also given to the limitations of the current model configuration.

Large, M. J.; Pearce, J. V.

2014-07-01

172

Freeze-drying for morphological control of high performance semi-interpenetrating polymer networks. III  

NASA Technical Reports Server (NTRS)

The feasibility of using a freeze-drying (solvent removal by sublimation) approach for controlling the morphology of a high-performance semi-IPN is assessed. A high-performance thermoplastic polyimide and commercially available 4,4'-bismaleimide diphenylenemethane were dissolved in a solvent, 1,3,5-trioxane. The solvent was removed from the constituents by freeze-drying. For purposes of comparison, the constituents were dissolved in a high-boiling-point solvent, N,N-dimethylformamide. The solvent was removed from the solution by evaporation. The physical and mechanical properties and phase morphology of the neat resins and composites prepared by freeze-drying and traditional solution methods are presented and compared. It is concluded that the TG is higher and that the magnitude of minor constituent separation is less in the freeze-dry processed materials than for the processed solution.

Hsiung, H. J.; Hansen, M. G.; Pater, R. H.

1991-01-01

173

Microphysical Modelling of the 1999-2000 Arctic Winter. 3; Impact of Homogeneous Freezing on PSCs  

NASA Technical Reports Server (NTRS)

Simulations of the 1999-2000 winter have tested the effect on polar stratospheric clouds (PSCs) of the homogeneous freezing of liquid ternary solutions into nitric acid trihydrate (NAT) and nitric acid dihydrate (NAD). Proposed laboratory-derived volume-based and surface-based homogeneous freezing rates have both been examined, including different assumptions about the extrapolation of laboratory measurements to atmospheric conditions. Widespread PSC formation and denitrification are possible in several of the scenarios examined. However, the simulations are all unable to explain the solid-phase PSCs observed early in the 1999-2000 winter, and are unable to reproduce the measured extent of vortex denitrification. These problems can both be attributed to the relatively cold temperatures, more than 5 K below the NAT condensation point, necessary for effective homogeneous freezing. Therefore synoptic-scale homogeneous freezing appears unlikely to be the primary mechanism responsible for solid-phase PSC formation.

Drdla, K.

2003-01-01

174

Freezing of gait in Chinese patients with Parkinson disease.  

PubMed

A total of 474 Chinese Parkinson disease (PD) patients were evaluated to explore the prevalence and clinical correlates of freezing of gait (FOG) in this cross-sectional study. Two hundred and twenty-one PD patients (46.62%) reported FOG (freezers). FOG occurred more frequently in older patients and patients with low limbs as the site of onset, longer disease duration and higher Hoehn and Yahr (H&Y) stage (P<0.05). After adjusting for confounding factors, the freezers had higher scores for the Unified PD Rating Scale (UPDRS) part III, Non-Motor Symptoms Scale (NMSS), PD Questionnaire 39 (PDQ-39), Hamilton Depression Scale (HAMD) and Hamilton Anxiety Scale (HAMA), and lower scores for the Mini-Mental status examination (MMSE), frontal assessment battery (FAB) and Montreal Cognitive Assessment (MoCA) compared with the non-freezers (P<0.05). The binary logistic regression analysis indicated that festination, falls, a high daily dose of levodopa, the use of a dopamine receptor agonist, a high H&Y stage, the severity of urinary symptoms and a high HAMD score were associated with FOG. FOG is a relatively common disabling symptom in Chinese PD patients. Patients that were older, or reported a longer disease duration, low limbs as the site of onset and a more severe disability were more likely to experience FOG. Non-motor symptoms, especially urinary symptoms and depression, may also be related to FOG. PMID:25043665

Ou, Ruwei; Guo, Xiaoyan; Song, Wei; Cao, Bei; Yang, Jing; Wei, Qianqian; Shao, Na; Shang, Huifang

2014-10-15

175

Motor Imagery in Unipolar Major Depression  

PubMed Central

Background: Motor imagery is a potential tool to investigate action representation, as it can provide insights into the processes of action planning and preparation. Recent studies suggest that depressed patients present specific impairment in mental rotation. The present study was designed to investigate the influence of unipolar depression on motor imagery ability. Methods: Fourteen right-handed patients meeting DSM-IV criteria for unipolar depression were compared to 14 matched healthy controls. Imagery ability was accessed by the timing correspondence between executed and imagined movements during a pointing task, involving strong spatiotemporal constraints (speed/accuracy trade-off paradigm). Results: Compared to controls, depressed patients showed marked motor slowing on both actual and imagined movements. Furthermore, we observed greater temporal discrepancies between actual and mental movements in depressed patients than in healthy controls. Lastly, depressed patients modulated, to some extent, mental movement durations according to the difficulty of the task, but this modulation was not as strong as that of healthy subjects. Conclusion: These results suggest that unipolar depression significantly affects the higher stages of action planning and point out a selective decline of motor prediction. PMID:25538580

Bennabi, Djamila; Monnin, Julie; Haffen, Emmanuel; Carvalho, Nicolas; Vandel, Pierre; Pozzo, Thierry; Papaxanthis, Charalambos

2014-01-01

176

Development and design of sludge freezing beds  

SciTech Connect

This study develops design criteria for a new sludge dewatering unit operation called a sludge freezing bed. This bed uses natural freeze-thaw to condition the sludge. The total depth of sludge that can be frozen, thawed and dewatered by this process in a year is the main criterion needed for design. Laboratory tests assessed the dewaterability of freeze-thaw conditioned water treatment plant sludge and both anaerobically and aerobically digested wastewater sludges at various depths. Mathematical models for predicting the design depth were developed; values for the input parameters to the models were obtained from the literature or from laboratory and pilot-scale experiments. The dewaterability tests indicated that the depth of sludge that can be applied is not limited by drainability. Up to 2.0 m of each sludge drained in minutes after freeze-thaw conditioning. Except for the aerobically digested sludge, the solids content after drainage is high enough to permit mechanical removal. The physical and thermal characteristics of frozen sludge were found to be equivalent to those of ice. An analysis of the freezing and thawing models reveals that the design of a freezing bed will depend on the duration and intensity of the freezing and thawing seasons.

Martel, C.J.

1988-12-01

177

[Alzheimer's disease and depression].  

PubMed

In Alzheimer's disease (AD) patients, depression is not rare. The prevalence of major depressive episodes has been reported to be within the range of 20-25% in AD patients, despite there being no association between the severity of AD and prevalence of comorbid depressive symptoms or diagnosed depression. Depression in AD patients is associated with greater impairment of the quality of life and an increased caregiver burden. As well as earlier placement in a nursing home, bio-psycho-social factors are also associated with the manifestation of depression in AD patients, and biological factors, such as the brain pathology, may be the main influence. Depressive mood, loss of interest, and anxiety are among the most marked symptoms of depression in AD patients. In comparison with major depressive disorder, in depression in AD, psychomotor retardation is more prominent, while, in major depressive disorder, somatic anxiety is more marked. In the treatment of depression in AD, non-pharmacological and pharmacological therapies are applied. Basically, support and encouragement are required. In addition, psychosocial interventions, such as validation, reminiscence, physical exercise, and interventions for caregivers of those with dementia have been reported to be useful. The results of RCT with antidepressants are inconsistent. As the efficacy of cholinesterase inhibitor for depression in AD has been reported, it is reasonable to initially provide treatment with cholinesterase inhibitors rather than antidepressant therapy. PMID:24450144

Mizukami, Katsuyoshi

2013-01-01

178

Freezing Characteristics of Droplet on a Cooled Wall  

NASA Astrophysics Data System (ADS)

An experimental study has been performed to investigate the freezing characteristics of an aqueous binary solution droplet on a cooled wall. Pure water, ethylene-glycol aqueous solutions of 1to 10 mass%, and NaCl aqueous solutions of 1 to 15 mass% in concentration were adopted as the testing solutions. The droplet was frozen under a variety of cooling conditions such as wall temperature, air temperature, air velocity, and solute concentration in both the static atmosphere and the cold air flow. The observations on both the freezing characteristics and the morphologies of the droplet were extensively carried out. In addition, the inside flow of the droplets were observed. It was found that the morphology of the droplet on the cooled wall varied markedly depending on the solution, which appears to be mainly caused by the difference in the surface tension of the solution. On the other hand, under the conditions with a cold air flow, initial freezing point of the droplet was found to be mainly owing to the cooling rate between the cooled wall and the cold air.

Horibe, Akihiko; Fukusako, Shouichiro; Yamada, Masahiko

179

Elastic properties and freezing of argon confined in mesoporous glass  

NASA Astrophysics Data System (ADS)

We study the elastic properties of argon confined in mesoporous Vycor glass with a mean pore diameter of 8 nm. For this purpose volumetric adsorption and desorption measurements are combined with simultaneous ultrasonic measurements. Therewith we obtain the effective shear modulus as a function of the pore filling reflecting both the spatial arrangement and the freezing process of confined argon. Below the freezing point of argon the adsorption process proceeds in three steps. (I) The first adsorbed layers of argon do not contribute to the measured shear modulus, i.e., they do not behave like a solid. (II) In an intermediate range of pore filling the shear modulus increases linearly with increasing amount of adsorbate, i.e., the process of freezing starts, probably with the formation of capillary sublimate. (III) At a certain filling fraction an abrupt rise of the shear modulus up to a plateau value is observed. This step indicates either a change in the spatial distribution of the capillary condensate or a change in its intrinsic properties. The lower the temperature, the smaller the characteristic filling fractions at which these transitions occur. During desorption a hysteresis of the shear modulus, of the attenuation, and hence of the state of the adsorbate is observed.

Schappert, Klaus; Pelster, Rolf

2008-11-01

180

Hot big bang or slow freeze?  

NASA Astrophysics Data System (ADS)

We confront the big bang for the beginning of the universe with an equivalent picture of a slow freeze - a very cold and slowly evolving universe. In the freeze picture the masses of elementary particles increase and the gravitational constant decreases with cosmic time, while the Newtonian attraction remains unchanged. The freeze and big bang pictures both describe the same observations or physical reality. We present a simple “crossover model” without a big bang singularity. In the infinite past space-time is flat. Our model is compatible with present observations, describing the generation of primordial density fluctuations during inflation as well as the present transition to a dark energy-dominated universe.

Wetterich, C.

2014-09-01

181

Depression and Heart Disease  

MedlinePLUS

... see the NIMH booklet on Depression . What is heart disease? Heart disease refers to a number of illnesses ... and save your life. How are depression and heart disease linked? People with heart disease are more likely ...

182

Background to Depression  

NSDL National Science Digital Library

Although writers have described episodes of depression since antiquity, only recently have we recognized that the depressive disorders are among the most common and disabling medical conditions throughout the world.

2009-04-14

183

How Does Depression Develop?  

MedlinePLUS

... these things alone may not be enough to cause depression, but several of them acting together can trigger ... is no single gene that controls mood or causes depression. However, your genetic makeup is important, because genes ...

184

Genetic biomarkers of depression  

PubMed Central

Depression is a term that has been used to describe a variety of ailments, ranging from minor to incapacitating. Clinically significant depression, termed as major depression, is a serious condition characterized not only by depressed mood but also by a cluster of somatic, cognitive, and motivational symptoms. Significant research efforts are aimed to understand the neurobiological as well as psychiatric disorders, and the evaluation of treatment of these disorders is still based solely on the assessment of symptoms. In order to identify the biological markers for depression, we have focused on gathering information on different factors responsible for depression including stress, genetic variations, neurotransmitters, and cytokines and chemokines previously suggested to be involved in the pathophysiology of depression. The present review illustrates the potential of biomarker profiling for psychiatric disorders, when conducted in large collections. The review highlighted the biomarker signatures for depression, warranting further investigation. PMID:22754217

Tamatam, Anand; Khanum, Farhath; Bawa, Amarinder Singh

2012-01-01

185

Method of treating depression  

DOEpatents

Methods for treatment of depression-related mood disorders in mammals, particularly humans are disclosed. The methods of the invention include administration of compounds capable of enhancing glutamate transporter activity in the brain of mammals suffering from depression. ATP-sensitive K.sup.+ channel openers and .beta.-lactam antibiotics are used to enhance glutamate transport and to treat depression-related mood disorders and depressive symptoms.

Henn, Fritz

2013-04-09

186

Method of treating depression  

DOEpatents

Methods for treatment of depression-related mood disorders in mammals, particularly humans are disclosed. The methods of the invention include administration of compounds capable of enhancing glutamate transporter activity in the brain of mammals suffering from depression. ATP-sensitive K.sup.+ channel openers and .beta.-lactam antibiotics are used to enhance glutamate transport and to treat depression-related mood disorders and depressive symptoms.

Henn, Fritz (East Patchogue, NY)

2012-01-24

187

Depression in Parkinson's disease.  

PubMed

The prevalence of major and minor depression in Parkinson's disease is around 30-40% but, unfortunately, depression remains frequently underrecognized and often undertreated. However, recognition and appropriate treatment of depression in patients with Parkinson's disease is essential for improving the cross-sectional picture and longitudinal course. This review focuses on the epidemiology, pathophysiology and different treatment modalities of depression in Parkinson's disease. PMID:25509363

Rihmer, Zoltán; Gonda, Xénia; Döme, Péter

2014-07-30

188

Use of manometric temperature measurement (MTM) and SMART freeze dryer technology for development of an optimized freeze-drying cycle.  

PubMed

This report provides, for the first time, a summary of experiments using SMART Freeze Dryer technology during a 9 month testing period. A minimum ice sublimation area of about 300 cm(2) for the laboratory freeze dryer, with a chamber volume 107.5 L, was found consistent with data obtained during previous experiments with a smaller freeze dryer (52 L). Good reproducibility was found for cycle design with different type of excipients, formulations, and vials used. SMART primary drying end point estimates were accurate in the majority of the experiments, but showed an over prediction of primary cycle time when the product did not fully achieve steady state conditions before the first MTM measurement was performed. Product resistance data for 5% sucrose mixtures at varying fill depths were very reproducible. Product temperature determined by SMART was typically in good agreement with thermocouple data through about 50% of primary drying time, with significant deviations occurring near the end of primary drying, as expected, but showing a bias much earlier in primary drying for high solid content formulations (16.6% Pfizer product) and polyvinylpyrrolidone (40 kDa) likely due to water "re-adsorption" by the amorphous product during the MTM test. PMID:17853427

Gieseler, Henning; Kramer, Tony; Pikal, Michael J

2007-12-01

189

Automated Assessment of Pavlovian Conditioned Freezing and Shock Reactivity in Mice Using the Video Freeze System  

PubMed Central

The Pavlovian conditioned freezing paradigm has become a prominent mouse and rat model of learning and memory, as well as of pathological fear. Due to its efficiency, reproducibility and well-defined neurobiology, the paradigm has become widely adopted in large-scale genetic and pharmacological screens. However, one major shortcoming of the use of freezing behavior has been that it has required the use of tedious hand scoring, or a variety of proprietary automated methods that are often poorly validated or difficult to obtain and implement. Here we report an extensive validation of the Video Freeze system in mice, a “turn-key” all-inclusive system for fear conditioning in small animals. Using digital video and near-infrared lighting, the system achieved outstanding performance in scoring both freezing and movement. Given the large-scale adoption of the conditioned freezing paradigm, we encourage similar validation of other automated systems for scoring freezing, or other behaviors. PMID:20953248

Anagnostaras, Stephan G.; Wood, Suzanne C.; Shuman, Tristan; Cai, Denise J.; LeDuc, Arthur D.; Zurn, Karl R.; Zurn, J. Brooks; Sage, Jennifer R.; Herrera, Gerald M.

2009-01-01

190

Depression and Chronic Illness  

MedlinePLUS

... and one-fifth with terminal cancer experience a depressive disorder. Sadly, less than half of those receive treatment for depression. Facing a chronic illness naturally leads to ... treatment as soon as depressive symptoms appear because early treatment is more likely ...

191

Depression during pregnancy  

Microsoft Academic Search

OBJECTIVE To review existing literature on depression during pregnancy and to provide information for family physicians in order to promote early detection and treatment. QUALITY OF EVIDENCE MEDLINE was searched from January 1989 through August 2004 using the key words depression, pregnancy, prenatal, and antenatal. Articles focusing on depression during pregnancy were chosen for review; these articles were based on

Deirdre Ryan; Lisa Milis; Nicholas Misri

2005-01-01

192

Threshold temperatures mediate the impact of reduced snow cover on overwintering freeze-tolerant caterpillars  

NASA Astrophysics Data System (ADS)

Decreases in snow cover due to climate change could alter the energetics and physiology of ectothermic animals that overwinter beneath snow, yet how snow cover interacts with physiological thresholds is unknown. We applied numerical simulation of overwintering metabolic rates coupled with field validation to determine the importance of snow cover and freezing to the overwintering lipid consumption of the freeze-tolerant Arctiid caterpillar Pyrrharctia isabella. Caterpillars that overwintered above the snow experienced mean temperatures 1.3°C lower than those below snow and consumed 18.36 mg less lipid of a total 68.97-mg reserve. Simulations showed that linear temperature effects on metabolic rate accounted for only 30% of the difference in lipid consumption. When metabolic suppression by freezing was included, 93% of the difference between animals that overwintered above and below snow was explained. Our results were robust to differences in temperature sensitivity of metabolic rate, changes in freezing point, and the magnitude of metabolic suppression by freezing. The majority of the energy savings was caused by the non-continuous reduction in metabolic rate due to freezing, the first example of the importance of temperature thresholds in the lipid use of overwintering insects.

Marshall, Katie E.; Sinclair, Brent J.

2012-01-01

193

SEM sample preparation for cells on 3D scaffolds by freeze-drying and HMDS.  

PubMed

Common dehydration methods of cells on biomaterials for scanning electron microscopy (SEM) include air drying, hexamethyldisilazane (HMDS) or tetramethysilane (TMS) treatment and critical point drying (CPD). On the other side, freeze-drying has been widely employed in dehydrating biological samples and also in preparing porous biomaterial scaffolds but not in preparing cells on three-dimensional (3D) biomaterials for SEM examination. In this study, we compare cells on porous hydroxyapatite (HA) prepared by air drying, HMDS and freeze-drying. The effects of fixation and using phosphate buffered saline (PBS) in the fixation were also assessed on three porous calcium phosphate (CaP) materials, namely, HA, ?-tricalcium phosphate (?-TCP) and ?-tricalcium phosphate (?-TCP) samples. There is no significant difference in samples prepared by HMDS treatment and freeze-drying viewed at low magnification. Besides, it is better not to use phosphate buffer in the fixation step for CaP materials to avoid undesirable spontaneous precipitation of CaPs. On the other hand, fewer exchanges of liquids are required for freeze-drying and hence chemical fixation may not be absolutely required for samples prepared by freeze-drying. Other technical details of the preparation were also investigated and discussed. This study suggests both HMDS and freeze-drying can be employed to dehydrate cells on 3D scaffolds for SEM examination. PMID:22532079

Lee, Juliana Tsz Yan; Chow, King Lau

2012-01-01

194

Relationship between heat transfer parameters and the characteristic damage variables for the freezing of beef.  

PubMed

One of the most suitable parameters for relating the freezing rate to the volume of drip produced during the thawing of meat is the characteristic time, defined as the time necessary to reduce the temperature of the sample from -1·1°C (initial freezing point in beef) to -7°C (80% of the water frozen). However, as the freezing of beef in factories takes place with important temperature gradients, distributions of these characteristic times must be expected along the pieces of frozen meat. In order to relate these characteristic time distributions to heat transfer parameters under industrial freezing conditions, a mathematical model which simulates the freezing of beef is developed in this paper. The model establishes the heat transfer equations with simultaneous change of phase, taking into account the dependence of the thermal properties with the ice content and considering the anisotropy of the thermal conductivity according to the direction of the fibres. Boundary conditions include the possibility of thermal resistances in the refrigerated interphase. The model developed was compared with laboratory experiments performed under factory freezing conditions and showed a satisfactory agreement between theory and experiment. PMID:22055769

Mascheroni, R H; Calvelo, A

1980-08-01

195

Simulations of Polar Stratospheric Clouds and Denitrification Using Laboratory Freezing Rates  

NASA Technical Reports Server (NTRS)

During the 1999-2000 Arctic winter, the SAGE (Stratospheric Aerosol and Gas Experiment) III Ozone Loss and Validation Experiment (SOLVE) provided evidence of widespread solid-phase polar stratospheric clouds (PSCs) accompanied by severe nitrification. Previous simulations have shown that a freezing process occurring at temperatures above the ice frost point is necessary to explain these observations. In this work, the nitric acid freezing rates measured by Salcedo et al. and discussed by Tabazadeh et al. have been examined. These freezing rates have been tested in winter-long microphysical simulations of the 1999-2000 Arctic vortex evolution in order to determine whether they can explain the observations. A range of cases have been explored, including whether the PSC particles are composed of nitric acid dihydrate or trihydrate, whether the freezing process is a bulk process or occurs only on the particle surfaces, and uncertainties in the derived freezing rates. Finally, the possibility that meteoritic debris enhances the freezing rate has also been examined. The results of these simulations have been compared with key PSC and denitrification measurements made by the SOLVE campaign. The cases that best reproduce the measurements will he highlighted, with a discussion of the implications for our understanding of PSCs.

Drdla, Katja; Tabazadeh, Azadeh; Gore, Warren J. (Technical Monitor)

2001-01-01

196

Importance of Depression in Diabetes.  

ERIC Educational Resources Information Center

Depression doubles the likelihood of comorbid depression, which presents as major depression in 11% and subsyndromal depression in 31% of patients with the medical illness. The course of depression is chronic, and afflicted patients suffer an average of one episode annually. Depression has unique importance in diabetes because of its association…

Lustman, Patrick J.; Clouse, Ray E.; Anderson, Ryan J.

197

9 CFR 590.536 - Freezing operations.  

Code of Federal Regulations, 2010 CFR

... FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EGG PRODUCTS INSPECTION INSPECTION OF EGGS AND EGG PRODUCTS (EGG PRODUCTS INSPECTION ACT) Sanitary, Processing, and Facility Requirements § 590.536 Freezing...

2010-01-01

198

9 CFR 590.534 - Freezing facilities.  

Code of Federal Regulations, 2010 CFR

... FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EGG PRODUCTS INSPECTION INSPECTION OF EGGS AND EGG PRODUCTS (EGG PRODUCTS INSPECTION ACT) Sanitary, Processing, and Facility Requirements § 590.534 Freezing...

2010-01-01

199

Cell-encapsulating droplet formation and freezing  

NASA Astrophysics Data System (ADS)

Cell-encapsulating droplets are vitrified for biopreservation applications. The dynamics of micro-droplet formation and its freezing mechanism are analyzed numerically and experimentally. In addition, the microdroplet encapsulation technique is applied to cryopreserve cells.

Ryoun Youn, Jae; Seok Song, Young

2012-09-01

200

Freeze Crystallization Processes: Efficiency by Flexibility  

E-print Network

Energy consumption in fractionating solutions by distillation and evaporation can be reduced by 70% to 90% by using freeze crystallization processes. The thermodynamic bases for the substantially lower energy requirements include: 1) The phase...

Heist, J. A.; Barron, T. S.

1983-01-01

201

Assessing Hail and Freeze Damage to Field Corn and Sorghum  

E-print Network

New Growth. Physical damage to young corn can be experienced from a freeze or heavy frost, from blowing sand and whipping in high winds, and from hail. Sometimes it may be a combination of several events. With each of these the growing point has... sunshine and temperatures above 55?F to support photosynthesis and to grow through any extended stress period once seed stores are depleted. Frost Damage (27 to 32?F). Tissue loss from frost damage is directly proportional to how low the temperature falls...

Livingston, Stephen

1995-11-30

202

Freezing tolerance of conifer seeds and germinants.  

PubMed

Survival after freezing was measured for seeds and germinants of four seedlots each of interior spruce (Picea glauca x engelmannii complex), lodgepole pine (Pinus contorta Dougl. ex Loud.), Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and western red cedar (Thuja plicata Donn ex D. Donn). Effects of eight seed treatments on post-freezing survival of seeds and germinants were tested: dry, imbibed and stratified seed, and seed placed in a growth chamber for 2, 5, 10, 15, 20 or 30 days in a 16-h photoperiod and a 22/17 degrees C thermoperiod. Survival was related to the water content of seeds and germinants, germination rate and seedlot origin. After freezing for 3 h at -196 degrees C, dry seed of most seedlots of interior spruce, Douglas-fir and western red cedar had 84-96% germination, whereas lodgepole pine seedlots had 53-82% germination. Freezing tolerance declined significantly after imbibition in lodgepole pine, Douglas-fir and interior spruce seed (western red cedar was not tested), and mean LT50 of imbibed seed of these species was -30, -24.5 and -20 degrees C, respectively. Freezing tolerance continued to decline to a minimum LT50 of -4 to -7 degrees C after 10 days in a growth chamber for interior spruce, Douglas-fir and lodgepole pine, or after 15 days for western red cedar. Minimum freezing tolerance was reached at the stage of rapid hypocotyl elongation. In all species, a slight increase in freezing tolerance of germinants was observed once cotyledons emerged from the seed coat. The decrease in freezing tolerance during the transition from dry to germinating seed correlated with increases in seed water content. Changes in freezing tolerance between 10 and 30 days in the growth chamber were not correlated with seedling water content. Within a species, seedlots differed significantly in freezing tolerance after 2 or 5 days in the growth chamber. Because all seedlots of interior spruce and lodgepole pine germinated quickly, there was no correlation between seedlot hardiness and rate of germination. Germination rate and freezing tolerance of Douglas-fir and western red cedar seedlots was negatively correlated. There was a significant correlation between LT50 after 10 days in the growth chamber and minimum spring temperature at the location of seedlot origin for interior spruce and three seedlots of western red cedar, but no relationship was apparent for lodgepole pine and Douglas-fir. PMID:14652223

Hawkins, B J; Guest, H J; Kolotelo, D

2003-12-01

203

Freezing Characteristics of Rigid Plant Tissues (Development of Cell Tension during Extracellular Freezing).  

PubMed

The freezing characteristics and development of cell tension during extracellular freezing were examined in supercooling stem tissues of riverbank grapes (Vitis riparia) and cold-hardened leaves of live oak (Quercus virginiana) and mountain cranberry (Vaccinium vitis-idaea). Dormant stem xylem and pith tissues of river-bank grapes were resistant to freeze-induced dehydration above the homogeneous nucleation temperature, and they developed cell tension reaching a maximum of 27 MPa. Similarly, extracellular freezing induced cell tension in the leaves of live oak and mountain cranberry. Maximum cell tension in the leaves of live oak was 16.8 MPa and 8.3 MPa in the leaves of mountain cranberry. Following peak tensions in the leaves, a decline in the pressure was observed with progressive freezing. The results suggest that resistance to cell deformation during extracellular freezing due to cell-wall rigidity can lead to reduced cell dehydration and increased cell tension. A relationship to predict freezing behavior in plant tissues based on cell rigidity is presented. Based on cell-water relations and ice nucleation rates, cell-wall rigidity has been shown to effect the freezing characteristics of plant tissues, including freeze-induced dehydration, supercooling, and homogeneous nucleation temperatures. PMID:12226313

Rajashekar, C. B.; Burke, M. J.

1996-06-01

204

Simulation of high pressure freezing processes by enthalpy method  

Microsoft Academic Search

High pressure freezing processes such as pressure assisted freezing (PAF) and high pressure shift freezing (HPSF) are novel technologies that can be used to improve the quality of frozen foods. A one dimensional finite difference numerical model based on the enthalpy formulation was developed to simulate high pressure freezing of tylose, agar gel and potatoes. The Schwartzberg equation was used

T. Norton; A. Delgado; E. Hogan; P. Grace; Da-Wen Sun

2009-01-01

205

Freezing and Thawing Human Embryonic Stem Cells  

NSDL National Science Digital Library

Lia Kent, of Stemgent's Research and Development team, has created this video to demonstrate "the proper technique for rapidly thawing hES cells from liquid nitrogen stocks, plating them on mouse embryonic feeder cells, and slowly freezing them for long-term storage." The video is also accompanied by protocols for thawing and freezing hES cells, discussion, materials, references, a forum for comments, and a PDF of the full text.

Kent, Lia

206

Winter depression and diabetes.  

PubMed

Depression is a common and often harmful disorder, which is frequently associated with the winter season. Research has shown a link between type 2 diabetes mellitus and depression. Furthermore, diabetics with depression have a higher rate of adverse outcomes. Little has been published regarding the seasonality of depression in diabetics. The case report described in this article concerns a 65-year-old woman with type 2 diabetes and a history of winter depression. Current evidence-based management options are reviewed. PMID:23089656

Ernst, Christine R

2012-12-01

207

Spacecraft Radiator Freeze Protection Using a Regenerative Heat Exchanger with Bypass Setpoint Temperature Control  

NASA Technical Reports Server (NTRS)

Spacecraft radiators are sized for their maximum heat load in their warmest thermal environment, but must operate at reduced heat loads and in colder environments. For systems where the radiator environment can be colder than the working fluid freezing temperature, radiator freezing becomes an issue. Radiator freezing has not been a major issue for the Space Shuttle and the International Space Station (ISS) active thermal control systems (ATCSs) because they operate in environments that are warm relative to the freezing point of their external coolants (Freon-21 and ammonia, respectively). For a vehicle that lands at the Lunar South Pole, the design thermal environment is 215K, but the radiator working fluid must also be kept from freezing during the 0 K sink of transit. A radiator bypass flow control design such as those used on the Space Shuttle and ISS requires more than 30% of the design heat load to avoid radiator freezing during transit - even with a very low freezing point working fluid. By changing the traditional ATCS architecture to include a regenerating heat exchanger inboard of the radiator and by using a regenerator bypass flow control valve to maintain system setpoint, the required minimum heat load can be reduced by more than half. This gives the spacecraft much more flexibility in design and operation. The present work describes the regenerator bypass ATCS setpoint control methodology. It includes analytical results comparing the performance of this system to the traditional radiator bypass system. Finally, a summary of the advantages of the regenerator bypass system are presented.

Ungar, Eugene K.

2008-01-01

208

Basic concepts of depression  

PubMed Central

This paper reviews concepts of depression, including history and classification. The original broad concept of melancholia included all forms of quiet insanity. The term depression began to appear in the nineteenth century as did the modern concept of affective disorders, with the core disturbance now viewed as one of mood. The 1930s saw the introduction of defined criteria into official diagnostic schemes. The modern separation into unipolar and bipolar disorder was introduced following empirical research by Angst and Perris in the 1960s. The partially overlapping distinctions between psychotic and neurotic depression, and between endogenous and reactive depression, started to generate debate in the 1920s, with considerable multivariate research in the 1960s. The symptom element in endogenous depression currently survives in melancholia or somatic syndrome. Life stress is common in various depressive pictures. Dysthymia, a valuable diagnosis, represents a form of what was regarded earlier as neurotic depression. Other subtypes are also discussed. PMID:18979941

Paykel, Eugene S.

2008-01-01

209

Depressive symptoms in institutionalized older adults  

PubMed Central

OBJECTIVE To estimate the prevalence of depressive symptoms among institutionalized elderly individuals and to analyze factors associated with this condition. METHODS This was a cross-sectional study involving 462 individuals aged 60 or older, residents in long stay institutions in four Brazilian municipalities. The dependent variable was assessed using the 15-item Geriatric Depression Scale. Poisson’s regression was used to evaluate associations with co-variables. We investigated which variables were most relevant in terms of presence of depressive symptoms within the studied context through factor analysis. RESULTS Prevalence of depressive symptoms was 48.7%. The variables associated with depressive symptoms were: regular/bad/very bad self-rated health; comorbidities; hospitalizations; and lack of friends in the institution. Five components accounted for 49.2% of total variance of the sample: functioning, social support, sensory deficiency, institutionalization and health conditions. In the factor analysis, functionality and social support were the components which explained a large part of observed variance. CONCLUSIONS A high prevalence of depressive symptoms, with significant variation in distribution, was observed. Such results emphasize the importance of health conditions and functioning for institutionalized older individuals developing depression. They also point to the importance of providing opportunities for interaction among institutionalized individuals. PMID:24897042

Santiago, Lívia Maria; Mattos, Inês Echenique

2014-01-01

210

Panic disorder and depression: a psychodynamic exploration of comorbidity.  

PubMed

Eight of twenty-one patients presenting for treatment in an open trial of brief psychodynamic psychotherapy for panic disorder also carried the diagnosis of major depression. For the patients who completed the study, depression remitted as well as panic disorder. The authors highlight psychodynamic factors that they hypothesize may contribute to the significant overlap between panic disorder and depression, and describe three videotaped cases to illustrate these points. PMID:13678503

Rudden, Marie; Busch, Fredric N; Milrod, Barbara; Singer, Meriamne; Aronson, Andrew; Roiphe, Jean; Shapiro, Theodore

2003-08-01

211

[Cognitive deficits in unipolar major depression].  

PubMed

Cognitive deficits are common symptom presentations in neurology and psychiatry. Cognitive symptoms during major depressive episodes cause subjective distress as well as difficulties during therapy and psychosocial reintegration. Depression-associated cognitive symptoms are characterized by a mood-congruent information processing bias as well as by cognitive performance deficits. A diagnostically relevant profile of neuropsychological impairments specific to depression has not yet been identified. Nevertheless, deficits of executive and declarative memory functions have repeatedly been reported. The time course of cognitive deficits after remission of mood is not entirely clear. Depending on the point of time of the reinvestigation, patients may still exhibit pronounced cognitive deficits. This article presents the current knowledge about cognitive symptoms in major depression, including the pathophysiology and treatment options. PMID:25604917

Konrad, C; Losekam, S; Zavorotnyy, M

2015-01-01

212

DNA COMET ASSAY TO IDENTIFY DIFFERENT FREEZING TEMPERATURES OF IRRADIATED LIVER CHICKEN  

Microsoft Academic Search

The cold chain is a succession of steps which maintain the food at low temperature. The thawed food never be frozen again and the best solution being to consume it quickly to avoid the microorganism growth which causes decay and nutrients damage. One of most important point is that freezing process, unlike irradiation, do not destroy microorganisms, only inactive them

Renato C. Duarte; Michel A. Mozeika; Gustavo B. Fanaro; Eric Marchioni; Anna L. C. H. Villavicencio

213

Cryoprotectants for freeze drying of drug nano-suspensions: effect of freezing rate.  

PubMed

Drug nanoparticles are often prepared in a liquid medium, and a drying method such as freeze drying is used to convert them to an oral solid dosage form. When the dried form is reconstituted in an aqueous system, it may be redispersed to achieve its original particle size. The redispersibility of dried nanoparticles depends on the parameters of the freeze drying process. In this study, an apparatus with a freezing rate gradient was used to systematically investigate the effect of cryoprotectants on the redispersibility of nanoparticles as a function of freezing rate. Sucrose, lactose, mannitol, and polyethylene glycol were used as cryoprotectants for a naproxen nano-suspension. A fast freezing rate and a high cryoprotectant concentration were generally favored. However, under certain conditions, a slower freezing rate resulted in better redispersibility. This is probably because slow freezing can produce a more cryo-concentrated liquid phase, and the concentrated cryoprotectant in the liquid phase can more effectively protect the nanoparticles. An irreversible aggregation map was constructed as a function of the freezing rate and the cryoprotectant concentration, and shows both the favorable and unfavorable effects of cryoprotectants. PMID:19475555

Lee, Min Kyung; Kim, Min Young; Kim, Sujung; Lee, Jonghwi

2009-12-01

214

Freeze Tolerance of Nine Zoysiagrass Cultivars Using Natural Cold Acclimation and Freeze Chambers  

Technology Transfer Automated Retrieval System (TEKTRAN)

Winter hardiness of zoysiagrass (Zoysia spp.) cultivars is an important attribute throughout the biogeographical transition zone, thus the inability to withstand freezing temperatures may limit the use of these cultivars. The objective of this research was to determine the freeze tolerance (LT50) of...

215

Depression and Bulimia: The Link Between Depression and Bulimic Cognitions  

Microsoft Academic Search

This study assessed the link between bulimic and depressive cognitions. Twenty-nine bulimics and 16 controls from the general population were first assessed on levels of depression using the Schedule for Affective Disorders and Schizophrenia–Change Version and the Beck Depression Inventory (BDI). Bulimics were significantly more depressed than controls. Bulimics differed significantly from controls on all cognitive measures associated with depression

Barbara Schlesier-Carter; Sharon A. Hamilton; Patrick M. ONeil; R. Bruce Lydiard; Robert Malcolm

1989-01-01

216

Embodied intervention reduce depression  

NASA Astrophysics Data System (ADS)

To investigate the difference of the selected-rate of undergraduates' depression with respect to time, gender and scales and the intervention effect of embodied exercise, 201 Undergraduates were measured with Self-Rating Depression Scale and Beck Depression Inventory (BDI).The result shows there are significant difference of the selected-rates of undergraduates' depression resulted from long-time interval rather than from short-time interval and gender. After the intervention, the selected-rates are decreased and no significant difference has been found between the embodied groups and the controlled group. Only the embodied groups maintain the better effects of the intervention in the tracking. Also the result shows that only the participants of embodied groups obtain more positive emotional experience. We conclude that there is significant difference of selected-rate of undergraduates' depression on scales, and the embodied exercise can effectively reduce undergraduate's depression.

Song, Dong-Qing; Bi, Xin; Fu, Ying

2011-10-01

217

Ethiopathogenesis of Depressive Disorders  

PubMed Central

Etiology of depressive disorders is still unknown. Several factors are involved in its pathophysiology such as neurotransmitters and neuroendocrine alterations, genetics, life events and their appraisal. Some of these components are strictly linked. Subjects with a family member affected by mood disorders are more prone to suffer from depressive disorders. It is also true that receiving feedbacks of indifference or neglect during childhood from one parent who suffer from depression may represent a factor of vulnerability. Indeed, reaction to a specific negative event may determine an increased allostasis which lead to a depressive episode. Thus, a psychological cause does not exclude a neurobiological cascade. Whereas in other cases recurrent depressive episodes appear in absence of any negative life event. This review provides a set of data regarding the current etiopathogenesis models of depression, with a particular attention to the neurobiological correlates and vulnerability factors. PMID:25614753

Pasquini, M; Berardelli, I; Biondi, M

2014-01-01

218

Vitamin D and depression.  

PubMed

Vitamin D is an essential nutrient proven to be important for bone health. It has other physiological functions, and there are plausible reasons for investigating vitamin D in depressive disorders. Some cross-sectional clinical and epidemiologic studies, but not all studies, have found that low levels of vitamin D are significantly associated with higher levels of depressive symptoms or with a depression diagnosis. However, cross-sectional studies cannot establish causality, and the methodology of these studies has been criticized. Due to the poor quality of the treatment studies, the effectiveness of vitamin D for depression cannot be adequately assessed. Current evidence does not definitively demonstrate that vitamin D deficiency is a cause of or risk for developing depression or that vitamin D is an effective therapy for depression. PMID:21261225

Howland, Robert H

2011-02-01

219

Sexual dysfunctions in depression.  

PubMed

The incidence of sexual dysfunctions in a group of 51 drug-free depressed patients and in age- and sex-matched controls was studied. Three groups of sexual dysfunction were assessed: alterations of libido, genital symptoms, and menstrual irregularities. The Beck Rating Scale for Depression, the Eysenck Personality Inventory (EPI), and the State-Trait Anxiety Inventory were completed on each participant. Depressed patients obtained significantly higher scores on anxiety, depression, and alterations of libido than controls. Rating scale scores for anxiety and depression were strongly intercorrelated, making the separation of depression-related symptoms from anxiety difficult. In males, the genital symptoms correlated inversely with the L (lie) score of the Eysenck Personality Inventory. There were no interrelationships between the three groups of sexual dysfunction. PMID:7149967

Mathew, R J; Weinman, M L

1982-08-01

220

Freeze drying for morphological control of inter-penetrating polymer networks  

NASA Technical Reports Server (NTRS)

The intrinsic brittleness of BMI resins can be reduced through the creation of an interpenetrating network (IPN) of BMI with a reactive-encapped thermoplastic, such as the presently considered polyimidesulfone, PISO2. The PISO2 and BMI were dissolved in a common solvent, which was then removed from the constituents by freeze drying; in an alternative method, an IPN was formed through dissolution of the constituent in a common solvent with either high or low melting point, followed by evaporative removal of the solvent. The effectiveness of the freeze-drying approach for morphological control is evaluated.

Hansen, Marion G.; Pater, Ruth H.

1990-01-01

221

An Integrative Ambient Agent Model for Unipolar Depression Relapse Prevention  

E-print Network

. Finally, it is pointed out how this model can be used in depression therapy, supported by an ambient agentAn Integrative Ambient Agent Model for Unipolar Depression Relapse Prevention Azizi Ab Aziz, Michel C.A. Klein, and Jan Treur Agent Systems Research Group, Department of Artificial Intelligence

Treur, Jan

222

Freezing-thawing action in the deterioration of the stones of Chambord Castle  

NASA Astrophysics Data System (ADS)

Limestone is very common in architecture (monuments and cultural heritage buildings) and used in the sculptures. The soft and porous limestone soaks up water and show weathering patterns and forms: alveolar weathering, granular disintegration, efflorescences. Freezing-thawing actions can be considered as one of the processes that contribute in the deterioration of stones located in the "cold regions" characterized with air temperatures below freezing point temperature. The amount of water within the pore space of the stones is a crucial factor of the decay. The experimental work presented in this paper is a part of a research program that aims to study the mechanisms that lead to the degradation of stone building materials due to the variation of climatic conditions. The analysis of the meteorological data of the field around the castle of Chambord shows the magnitude of temperature variations and the frequency of freezing-thawing cycles. The critical degrees of saturation at which the stone start to deteriorate after treatment with freezing-thawing cycles were examined in the tests conducted. The study concerns two porous limestone used in the construction and conservation of Chambord castle; highly porous Tuffeau stone having a total porosity of about 48 %, and medium porous Richemont stone with a total porosity of 27 %. Richemont stone has been used as a substitute stone of the degraded Tuffeau stone on the castle. The main physical properties, total porosity, apparent dry density and skeleton density and sound velocity for mechanical properties were measured for the stone samples before and during freezing-thawing cycles. ASTM (D5312-04) procedure was applied in the freezing-thawing tests. Tuffeau and Richmond samples were prepared at nine different degrees of saturations; 0, 20, 40, 70, 80, 85, 90, 95 and 100%, and properties were measured after different freezing-thawing cycles conditions; 2, 4, 8, 12, 16, 20, 30 and 50 cycles. The results of these tests show that when the degree of saturation exceeds 80-85%, freeze-thaw damage is inevitable even for a very few freeze-thaw cycles. Moreover, results indicate that the two studied stones have similar critical degree of saturation of about 85 %. This can be attributed to the similar percentage of macro-pores in the two tested stones. Finally, the critical degree of saturation was not changed after increasing the number of freezing-thawing cycles, thus the critical degree of saturation can be considered as a stone property.

Alomari, Asaad; Brunetaud, Xavier; Beck, Kevin; Al-Mukhtar, Muzahim

2013-04-01

223

Depression in women  

Microsoft Academic Search

Depression is the leading cause of disease-related disability in women. Epidemiological studies have shown that the lifetime prevalence of a major depressive disorder in women (21.3%) is almost twice that in men (12.7%). This ratio has been documented in different countries and ethnic groups. Sex differences relating to depression vary with age, with male and female children showing similar incidence

Rudolf E. Noble

2005-01-01

224

Depression symptoms during pregnancy  

Microsoft Academic Search

Summary  Pregnancy impacts common symptoms of major depressive disorder (MDD), such as energy, appetite, weight change, and sleep and\\u000a somatic complaints. However, it is not known whether the presentation of depression during pregnancy is different from that\\u000a at other times in women’s lives. This study compares the severity of symptoms of depression in 61 pregnant women with MDD\\u000a (PD), 50 nonpregnant

R. Manber; C. Blasey; J. J. B. Allen

2008-01-01

225

Neurobiology of Depression  

Microsoft Academic Search

Current treatments for depression are inadequate for many individuals, and progress in understanding the neurobiology of depression is slow. Several promising hypotheses of depression and antidepressant action have been formulated recently. These hypotheses are based largely on dysregulation of the hypothalamic-pituitary-adrenal axis and hippocampus and implicate corticotropin-releasing factor, glucocorticoids, brain-derived neurotrophic factor, and CREB. Recent work has looked beyond hippocampus

Eric J. Nestler; Michel Barrot; Ralph J. DiLeone; Amelia J. Eisch; Stephen J. Gold; Lisa M. Monteggia

2002-01-01

226

Parasuicide, anhedonia, and depression.  

PubMed

Previous research has shown that anhedonia characterizes suicide attempters. The present study aimed to replicate this finding using the level of depression as a control. Seventy-three depressed parasuicides, 30 nondepressed parasuicides, and 104 matched controls were assessed on the Revised Physical Anhedonia Scale (PAS). Consistent with previous studies, depressed parasuicides were significantly more anhedonic than controls, but nondepressed parasuicides were not significantly more anhedonic than controls. Moreover, multiple linear regression analysis showed that the PAS score explained a negligible part of the variance in the distinction between parasuicides and controls. Anhedonia in parasuicides constitutes a depressive feature and not a temperamental trait. PMID:11011833

Loas, G; Perot, J M; Chignague, J F; Trespalacios, H; Delahousse, J

2000-01-01

227

Directional freezing for large volume cryopreservation.  

PubMed

Cryopreservation is currently the method of choice when it comes to long-term preservation of viable biological samples. The process, and consequently the volume of the sample, however, is limited by the ability to achieve homogenous and efficient heat removal. When this cannot be properly managed, ice crystals will grow uncontrollably resulting in extensive damage to the cryopreserved cells or tissues. Directional freezing is a technique that can be used to precisely control heat dissipation and ice crystal growth and morphology even when freezing large volumes. The technique has been used over the years to cryopreserve spermatozoa, oocytes, embryos, tissue slices and whole organs from a wide variety of domestic and wild species. In this chapter a protocol for directional freezing of spermatozoa is described and its benefits and shortcomings are discussed. PMID:25428019

Saragusty, Joseph

2015-01-01

228

Depression-like deficits in rats improved by subchronic modafinil  

Microsoft Academic Search

Rationale  Attentional and sensorimotor gating deficits in human depression are observed as residual symptoms irrespective of antidepressant\\u000a treatment. Clinical studies point to a benefit of modafinil in depression. No data are available on modafinil effects in depression-like\\u000a animal models.\\u000a \\u000a \\u000a \\u000a Objectives  We investigated effects of modafinil on attention and sensorimotor gating after subchronic treatment during a restraint stress\\u000a protocol inducing depression-like changes in

Ralf Regenthal; Holger Koch; Christian Köhler; Rainer Preiss; Ute Krügel

2009-01-01

229

Freeze fracture through the cytoskeleton, nucleus and nuclear matrix of lymphocytes studied by scanning electron microscopy.  

PubMed

The technique of delaying fixation until after freeze-fracture and thawing, described in an earlier paper (Haggis & Bond, 1979), has been developed further for study of cells in culture, principally mouse lymphocytes stimulated by concanavalin A. Using a thin layer of cells, a cryoprotectant concentration of either 10% glycerol or dimethylsulphoxide, is sufficient to give good structural preservation after rapid freezing and thawing. Nuclear matrices and Triton-permeabilized cells have been prepared from stimulated lymphocytes for comparative study. Polylysine-coated fibrin support films have been found to provide a convenient means of handling cells and subcellular preparations during freeze fracture, critical point drying and mounting for high-resolution scanning electron microscopy. PMID:6685772

Haggis, G H; Schweitzer, I; Hall, R; Bladon, T

1983-11-01

230

Melting and freezing of argon in a granular packing of linear mesopore arrays  

E-print Network

Freezing and melting of Ar condensed in a granular packing of template-grown arrays of linear mesopores (SBA-15, mean pore diameter 8 nanometer) has been studied by specific heat measurements C as a function of fractional filling of the pores. While interfacial melting leads to a single melting peak in C, homogeneous and heterogeneous freezing along with a delayering transition for partial fillings of the pores result in a complex freezing mechanism explainable only by a consideration of regular adsorption sites (in the cylindrical mesopores) and irregular adsorption sites (in niches of the rough external surfaces of the grains, and at points of mutual contact of the powder grains). The tensile pressure release upon reaching bulk liquid/vapor coexistence quantitatively accounts for an upward shift of the melting/freeezing temperature observed while overfilling the mesopores.

Christof Schaefer; Tommy Hofmann; Dirk Wallacher; Patrick Huber; Klaus Knorr

2008-03-29

231

Stratospheric Polar Freezing Belt Causes Denitrification  

NASA Technical Reports Server (NTRS)

Trajectory cloud model calculations are presented to show that homogeneous freezing of nitric acid hydrates can produce a polar freezing belt in both hemispheres that can cause denitrification. While hydrate cloud microphysical properties are similar over both poles, the shorter persistence of clouds in the Arctic prevents the depth of the denitrified layers from growing beyond a few kilometers. The 1999-2000 Arctic winter is unique in showing a distinct denitrification profile with a depth of approx. 4.5 km that is nearly half as deep as that computed for a typical Antarctic winter.

Tabazadeh, A.; Jensen, E. J.; Toon, O. B.; Drdla, K.; Schoeberl, M. R.; Gore, Warren J. (Technical Monitor)

2001-01-01

232

Importance of using complementary process analyzers for the process monitoring, analysis, and understanding of freeze drying.  

PubMed

The aim of the present paper is to demonstrate the importance of using complementary process analyzers (PAT tools) for the process monitoring, analysis, and understanding of freeze drying. A mannitol solution was used as a model system. Raman spectroscopic, near-infrared (NIR) spectroscopic, plasma emission spectroscopic, and wireless temperature measurements (TEMPRIS) were simultaneously performed in-line and real-time during each freeze-drying experiment. The combination of these four process analyzers to monitor a freeze-drying process is unique. The Raman and NIR data were analyzed using principal component analysis (PCA) and multivariate curve resolution (MCR), while the plasma emission spectroscopic and wireless temperature measurement data were analyzed using univariate data analysis. It was shown that the considered process analyzers do not only complement but also mutually confirm each other with respect to process step end points, physical phenomena occurring during freeze drying (process understanding), and product characterization (solid state). Furthermore and most important, the combined use of the process analyzers helped to identify flaws in previous studies in which these process analyzers were studied individually. Process analyzers might wrongly indicate that some process steps are fulfilled. Finally, combining the studied process analyzers also showed that more information per process analyzer can be obtained than previously described. A combination of Raman and plasma emission spectroscopy seems favorable for the monitoring of nearly all critical freeze-drying process aspects. PMID:19681620

De Beer, T R M; Wiggenhorn, M; Veillon, R; Debacq, C; Mayeresse, Y; Moreau, B; Burggraeve, A; Quinten, T; Friess, W; Winter, G; Vervaet, C; Remon, J P; Baeyens, W R G

2009-09-15

233

Infrared Thermography for Monitoring of Freeze-Drying Processes: Instrumental Developments and Preliminary Results  

PubMed Central

Coupling an infrared (IR) camera to a freeze dryer for on-line monitoring of freeze-drying cycles is described for the first time. Normally, product temperature is measured using a few invasive Pt-100 probes, resulting in poor spatial resolution. To overcome this, an IR camera was placed on a process-scale freeze dryer. Imaging took place every 120 s through a Germanium window comprising 30,000 measurement points obtained contact-free from ?40°C to 25°C. Results are presented for an empty system, bulk drying of cheese slurry, and drying of 1 mL human serum in 150 vials. During freezing of the empty system, differences of more than 5°C were measured on the shelf. Adding a tray to the empty system, a difference of more than 8°C was observed. These temperature differences probably cause different ice structures affecting the drying speed during sublimation. A temperature difference of maximum 13°C was observed in bulk mode during sublimation. When drying in vials, differences of more than 10°C were observed. Gradually, the large temperature differences disappeared during secondary drying and products were transformed into uniformly dry cakes. The experimental data show that the IR camera is a highly versatile on-line monitoring tool for different kinds of freeze-drying processes. © 2014 European Union 103:2088–2097, 2014 PMID:24902839

Emteborg, Håkan; Zeleny, Reinhard; Charoud-Got, Jean; Martos, Gustavo; Lüddeke, Jörg; Schellin, Holger; Teipel, Katharina

2014-01-01

234

Infrared thermography for monitoring of freeze-drying processes: instrumental developments and preliminary results.  

PubMed

Coupling an infrared (IR) camera to a freeze dryer for on-line monitoring of freeze-drying cycles is described for the first time. Normally, product temperature is measured using a few invasive Pt-100 probes, resulting in poor spatial resolution. To overcome this, an IR camera was placed on a process-scale freeze dryer. Imaging took place every 120 s through a Germanium window comprising 30,000 measurement points obtained contact-free from -40 °C to 25 °C. Results are presented for an empty system, bulk drying of cheese slurry, and drying of 1 mL human serum in 150 vials. During freezing of the empty system, differences of more than 5 °C were measured on the shelf. Adding a tray to the empty system, a difference of more than 8 °C was observed. These temperature differences probably cause different ice structures affecting the drying speed during sublimation. A temperature difference of maximum 13 °C was observed in bulk mode during sublimation. When drying in vials, differences of more than 10 °C were observed. Gradually, the large temperature differences disappeared during secondary drying and products were transformed into uniformly dry cakes. The experimental data show that the IR camera is a highly versatile on-line monitoring tool for different kinds of freeze-drying processes. PMID:24902839

Emteborg, Håkan; Zeleny, Reinhard; Charoud-Got, Jean; Martos, Gustavo; Lüddeke, Jörg; Schellin, Holger; Teipel, Katharina

2014-07-01

235

Depression and High School Students  

MedlinePLUS

... form of psychosis, such as hallucinations and delusions. Seasonal affective disorder—depression that begins during the winter months and lifts during spring and summer. Q. What causes depression? A. Depression does not have a single ...

236

Viscosity Depressants for Coal Liquefaction  

NASA Technical Reports Server (NTRS)

Proposed process modification incorporates viscosity depressants to prevent coal from solidifying during liquefaction. Depressants reduce amount of heat needed to liquefy coal. Possible depressants are metallic soaps, such as stearate, and amides, such as stearamide and dimer acid amides.

Kalfayan, S. H.

1983-01-01

237

Depression in patients with chronic venous ulceration.  

PubMed

As leg ulcer research has generally focused on aspects of treatment, the psychosocial impact of leg ulceration remains understudied. This article reports the findings of a study exploring the prevalence of anxiety and depression in 190 patients with chronic venous ulceration across 9 Trusts in the northwest of England. The hospital anxiety and depression scale (HADS) was used to screen patients for the presence of anxiety and depression using a cut-off point of 9 for level of "caseness". A total of 52 (27%) people scored as depressed while 50 (26%) scored as anxious. The two symptoms which appeared to be associated with anxiety and depression were pain and odour, while there was no association found between living alone, mobility and exudate. These findings suggest that the focus of care needs to be redirected for many patients for whom cure is not an option, but who are left to live with a chronic wound. Furthermore, psychological factors, including depression, should be a focus in assessment and ongoing review of patients with leg ulceration. PMID:16835511

Jones, June; Barr, Wally; Robinson, Jude; Carlisle, Caroline

238

The Goldman Consensus statement on depression in multiple sclerosis Goldman Consensus Group*  

E-print Network

, and clinical management for depressive affective disorders among patients suffering from MS. Multiple Sclerosis (2005) 11, 328Á/337 Key words: affective disorders; cognition; depression; multiple sclerosis of lifetime risk for depressive spec- trum disorders are quite high in persons diagnosed with MS.4 Point

Dennis, Nancy

239

Comparative validity of three screening questionnaires for DSM-IV depressive disorders and physicians’ diagnoses  

Microsoft Academic Search

Background: The aim of this study was to compare the validity of the Hospital Anxiety and Depression Scale (HADS), the WHO (five) Well Being Index (WBI-5), the Patient Health Questionnaire (PHQ), and physicians’ recognition of depressive disorders, and to recommend specific cut-off points for clinical decision making. Methods: A total of 501 outpatients completed each of the three depression screening

Bernd Löwe; Robert L. Spitzer; Kerstin Gräfe; Kurt Kroenke; Andrea Quenter; Stephan Zipfel; Christine Buchholz; Steffen Witte; Wolfgang Herzog

2004-01-01

240

Sudden Gains and Critical Sessions in Cognitive—Behavioral Therapy for Depression  

Microsoft Academic Search

In this study of cognitive—behavioral therapy for depression, many patients experienced large symptom improvements in a single between-sessions interval. These sudden gains' average magnitude was 11 Beck Depression Inventory points, accounting for 50% of these patients' total improvement. Patients who experienced sudden gains were less depressed than the other patients at posttreatment, and they remained so 18 months later. Substantial

Tony Z. Tang; Robert J. DeRubeis

2000-01-01

241

Depression in China: Integrating Developmental Psychopathology and Cultural-Clinical Psychology  

ERIC Educational Resources Information Center

With a starting point in John Abela's groundbreaking developmental psychopathology research on adolescent depression in China, we aimed to review the state of the literature on Chinese depression across the lifespan. We began with Dr. Abela's published studies relevant to depression in China and our own research with adults before turning to the…

Ryder, Andrew G.; Sun, Jiahong; Zhu, Xiongzhao; Yao, Shuqiao; Chentsova-Dutton, Yulia E.

2012-01-01

242

Seasonal freeze resistance of rainbow smelt (Osmerus mordax) is generated by differential expression of glycerol-3-phosphate dehydrogenase, phosphoenolpyruvate carboxykinase, and antifreeze protein genes.  

PubMed

In winter, rainbow smelt (Osmerus mordax) accumulate glycerol and produce an antifreeze protein (AFP), which both contribute to freeze resistance. The role of differential gene expression in the seasonal pattern of these adaptations was investigated. First, cDNAs encoding smelt and Atlantic salmon (Salmo salar) phosphoenolpyruvate carboxykinase (PEPCK) and smelt glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were cloned so that all sequences required for expression analysis would be available. Using quantitative PCR, expression of beta actin in rainbow smelt liver was compared with that of GAPDH in order to determine its validity as a reference gene. Then, levels of glycerol-3-phosphate dehydrogenase (GPDH), PEPCK, and AFP relative to beta actin were measured in smelt liver over a fall-winter-spring interval. Levels of GPDH mRNA increased in the fall just before plasma glycerol accumulation, implying a driving role in glycerol synthesis. GPDH mRNA levels then declined during winter, well in advance of serum glycerol, suggesting the possibility of GPDH enzyme or glycerol conservation in smelt during the winter months. PEPCK mRNA levels rose in parallel with serum glycerol in the fall, consistent with an increasing requirement for amino acids as metabolic precursors, remained elevated for much of the winter, and then declined in advance of the decline in plasma glycerol. AFP mRNA was elevated at the onset of fall sampling in October and remained elevated until April, implying separate regulation from GPDH and PEPCK. Thus, winter freezing point depression in smelt appears to result from a seasonal cycle of GPDH gene expression, with an ensuing increase in the expression of PEPCK, and a similar but independent cycle of AFP gene expression. PMID:16555199

Liebscher, Ryan S; Richards, Robert C; Lewis, Johanne M; Short, Connie E; Muise, Denise M; Driedzic, William R; Ewart, K Vanya

2006-01-01

243

Cytokines and depression: fortuitous or causative association?  

Microsoft Academic Search

There is an increasingly impressive database concerning the possible involvement of cytokines in depression and their role in the therapeutic effects of antidepressants. Based on the discussions which took place on these issues at a recent meeting held in Roscoff, France, this perspective summarizes in a critical way the evidence in favor of such a possibility, and points out the

R Dantzer; E Wollman; L Vitkovic; R Yirmiya

1999-01-01

244

Postpartum Depression: An Overview.  

ERIC Educational Resources Information Center

Occurring in about 12 percent of postpartum women, postpartum depression has been focus of considerable research. Variables that have been correlated with postpartum depression range from biological causes, to lack of social support, to relationship with husband, to attributional styles, to psychodynamic explanations. There is need for more…

Albright, Angela

1993-01-01

245

The Depression Coping Questionnaire.  

ERIC Educational Resources Information Center

College students (N=396), chronic pain patients (N=319), and schizophrenic veterans (N=43) completed the Depression Coping Questionnaire (DCQ) and the Beck Depression Inventory (BDI). Factor analysis of the DCQ identified eleven coping responses: social support, problem solving, self-blame/escape, aggression, indulgence, activities, medication,…

Kleinke, Chris L.

246

Older Adults and Depression  

MedlinePLUS

... who did not have the illness earlier in life. Brain chemistry— people with depression may have different brain chemistry than those without the illness. Stress— loss of a loved one, a difficult ... the first time later in life, the depression may be related to changes that ...

247

Depression Begets Depression: Comparing the Predictive Utility of Depression and Anxiety Symptoms to Later Depression  

ERIC Educational Resources Information Center

Background: The high comorbidity between depressive and anxiety disorders, especially among females, has called into question the independence of these two symptom groups. It is possible that childhood anxiety typically precedes depression in girls. Comparing of the predictive utility of symptoms of anxiety with the predictive utility of symptoms…

Keenan, Kate; Feng, Xin; Hipwell, Alison; Klostermann, Susan

2009-01-01

248

Parental Death and Depression  

Microsoft Academic Search

In this study an attempt was made to examine the association between depression and parental loss by death while avoiding some of the methodological problems that have plagued previous studies of this type. The Centre for Epidemiological Studies Depression Scale (CES-D) was administered to a sample of 1,250 patients in general practitioners' offices. Patients were asked to indicate whether they

Gordon E. Barnes; Harry Prosen

1985-01-01

249

Depression and ionizing radiation.  

PubMed

The objective of this at issue paper is the analysis of published data in correlation with the results of own research on the potential role of ionizing radiation in the genesis of depressive disorders. Depression is one of the most significant and long-term effect of the atomic bombings, nuclear testing and radiation emergences. The participants of the accident at the Chornobyl nuclear power plant increased prevalence of depression (18.0% and 13.1% in controls) and suicide rates. Depression is mainly observed in the structure of an organic mental disorder against cerebrovascular disease. The clinical pattern is dominated by asthenoadynamic and asthenoapathetic depression. Depressive disorders in radiation emergencies are multifactorial, that is the result of exposure to the complex psychogenic and radiological accident's factors, impact of traditional risk factors, somatic and neurological diseases, genetic predisposition, predisposition, etc. At the same time, exposure to ionizing radiation is a factor in the genesis of depression. This impact can be direct (to the Central Nervous System), and indirectly through the somatic and neurological abnormalities (multiorgan dysfunction) as well as by a variety of pathogenic mechanisms of ionizing radiation on the brain that have been discovered recently. It is strongly necessary analytical clinical and epidemiological studies with verification of depression and evidence-based establishment of the role of radiation and non-radiation risk factors. PMID:25191725

Loganovsky, K N; Vasilenko, Z L

2013-01-01

250

Real Stories of Depression  

MedlinePLUS Videos and Cool Tools

... and Depression Background on Educational Materials Resources for Health Care Providers Public Service Announcements (PSAs) Join A Study Depression Studies for Adults Contact Us Staff Directories Privacy ... The National Institute of Mental Health (NIMH) is part of the National Institutes of ...

251

Rupture of Cylindrical Ice Model and Tuna Fish during Freezing  

NASA Astrophysics Data System (ADS)

The gape and heave produced on the surface of tuna fish during freezing were confirmed by rupture of cylindrical type ice model. The results of experiment were shown as summarized below; 1) in case of restraining the progress of ice formation of model during freezing,any rupture was produced at not only slow freezing but also quick freezing. It was the same as tuna fish; 2) in case of closing surface of ice model covered perfectly by outside shell ice during slow freezing,it was not ruptured at not only ice model but also tuna fish. On the contrary it was cracked at quick freezing not only ice model but also tuna fish; 3) therefore it was confirmed that the rupture of tuna fish during freezing had been easy to produce at quick freezing.

Ogawa, Yutaka; Uno, Mitsuyo

252

47 CFR 64.1190 - Preferred carrier freezes.  

Code of Federal Regulations, 2010 CFR

...involve a charge to the subscriber. (e) Procedures for lifting preferred carrier freezes. All local exchange carriers who...a minimum, offer subscribers the following procedures for lifting a preferred carrier freeze: (1) A local exchange...

2010-10-01

253

Neurocognitive Functioning in Severe Depression.  

E-print Network

??Research has suggested that major depressive disorder can negatively impact neurocognitive functioning. Depression has been implicated in affecting many cognitive domains, including executive function, attention,… (more)

[No author

2006-01-01

254

Melting, freezing, and coalescence of gold nanoclusters  

Microsoft Academic Search

We present a detailed molecular-dynamics study of the melting, freezing, and coalescence of gold nanoclusters within the framework of the embedded-atom method. Concerning melting, we find the process first to affect the surface (``premelting''), then to proceed inwards. The curve for the melting temperature vs cluster size is found to agree reasonably well with predictions of phenomenological models based on

Laurent J. Lewis; Pablo Jensen; Jean-Louis Barrat

1997-01-01

255

Strangeness and QGP freeze-out dynamics  

E-print Network

We compare chemical and thermal analysis of the SPS Pb--Pb results at $158A$ GeV, and present a first chemical analysis of RHIC results. We show how a combined analysis of several strange hadron resonances can be used in a study of freeze-out dynamics.

Johann Rafelski; Giorgio Torrieri; Jean Letessier

2001-04-13

256

Hatchling Turtles Survive Freezing during Winter Hibernation  

Microsoft Academic Search

Hatchlings of the painted turtle (Chrysemys picta marginata) are unique as the only reptile and highest vertebrate life form known to tolerate the natural freezing of extracellular body fluids during winter hibernation. Turtles survived frequent exposures to temperatures as low as -6 degrees C to -8 degrees C in their shallow terrestrial nests over the 1987-1988 winter. Hatchlings collected in

Kenneth B. Storey; Janet M. Storey; Stephen P. J. Brooks; Thomas A. Churchill; Ronald J. Brooks

1988-01-01

257

FREEZE-FRAME: Fast Action Stress Relief.  

ERIC Educational Resources Information Center

Recent scientific research has proven that we can, not only manage our stress, we can even prevent it. Ways to achieve stress management are presented in this book. It details a method called FREEZE-FRAME, a process in which individuals mentally stop the chaos that surrounds them and then calmly contemplate their situation. The text opens with an…

Childre, Doc Lew

258

Theoretical prediction of 'optimal' freezing programmes.  

PubMed

We have developed a quantitative description of the osmotic behaviour of cells during freezing without a presupposed value of the cooling rate. Instead, at all times the intracellular supercooling is maximised provided that it does not exceed a predetermined value 'p' (e.g., 2 degrees C). This should preclude intracellular ice formation, but also ensures that the osmotic gradient and the CPA concentration gradient are limited, as well as the gradient driven transmembrane fluxes of water and CPA. Using the condition of a constant level of supercooling of p degrees C, equations can be derived to generate non-linear cooling curves in which at all times the cooling rate is maximised (to minimise slow cooling damage), while preventing conditions that could lead to fast cooling damage. Simulations of the osmotic events during freezing, and prediction of the 'optimal' freezing curve can be performed provided that values are available for the membrane permeability coefficients for water (L(p)) and cryoprotectant (P(s)), and their respective activation energies, the initial intracellular osmotically active aqueous volume, and the membrane surface area. Simulations are shown, both with and without permeant solute, to demonstrate how the predicted 'optimal' freezing curve is affected by medium composition, and by membrane permeability and osmotic cell characteristics. PMID:15615612

Woelders, H; Chaveiro, A

2004-12-01

259

[Depression as chronobiological illness].  

PubMed

Chronobiological problems are always present as aetiological or pathoplastic conditions almost in all psychiatric disorders and considered as the greatest contributors to the mood and sleep disorders associated problems. The present review summarise the recent advances in the chronobiology research from the point of the clinician with particular emphasis on the psychobiology and pharmacotherapy of the depression. Human behaviour builds up from different length of circadian, ultradian and seasonal rhytms, strictly controlled by a hierarchical organisation of sub-cellullar, cellular, neuro-humoral and neuro-immunological clock systems. These internal clock systems are orchestrated at molecular level by certain clock genes and on the other hand--at neuro-humoral level--by the effect of the sleep hormone, melatonine, produced by the neurons of the suprachiasmatic nucleus (SCN). Beside the biological factors, social interactions are also considered as important regulators of the biological clock systems. The pacemaker centers of the SCN receive efferents from the serotoninergic raphe nuclei in order to regulate stress responses and neuroimmunological functions. The direction and the level of the chronobiological desynchronisation could be totally divergent in the case of the different affective disorders. Different chronobiological interventions are required therefore in the case of the advanced and delayed sleep disorders. Sleeping disorders are considered as the most recognised signs of the chronobiological desynchronisation in depression, but these symptoms are only the tip of the iceberg, since other chronobiological symptoms could be present due to the hidden physiological abnormalities. The serum melatonine profile is considered to be characteristic to age, gender and certain neuropsychiatric disorders. The natural and synthetic agonist of the melatonine receptors could be used as chronobiotics. The recently marketed agomelatine with a highly selective receptor binding profile (MT1 and MT2 agonism and 5HT2C antagonism) targets the desynchronised circadian rhytm in affective disorders and it has mainly antidepressive effect. Among the non-pharmacological chronobiological interventions, the different forms of the sleep deprivation, light and social rhytm therapies could offer alternative treatment options for the clinician. PMID:19827314

Kálmán, Janos; Kálmán, Sára

2009-06-01

260

Psychodynamic treatment of depression.  

PubMed

Findings reviewed in this article show that PT should be included in treatment guidelines for depression. BPT in particular has been found to be superior to control conditions, equally effective as other active psychological treatments, with treatment effects that are often maintained in the long run, conferring resistance to relapse. Moreover, BPT is as effective as pharmacotherapy in the acute treatment of mild to moderate depression, and, either as monotherapy or combined with medication, BPT is associated with better long-term outcome compared with pharmacotherapy alone. PT is accepted by many depressed patients as a viable and preferred treatment. Furthermore, LTPT and PA have shown promise in treating patients with complex psychological disorders characterized by mood problems, often with comorbid personality problems. Finally, although studies suggest that effects of PT may be achieved somewhat slower compared with other forms of psychotherapy as well as medication in the acute treatment of depression, LTPT appears to be more clinically effective and perhaps more cost effective in the long run, particularly for chronically depressed patients. As noted, these conclusions need to be interpreted within the context of important limitations. Compared with other treatments, the evidence base for PT in depression remains relatively small, despite a respectable research tradition supporting psychodynamic assumptions with regard to the causation of depression. Moreover, and perhaps most importantly, although more studies now include longer follow-up assessments, our knowledge about the long-term effects of so-called evidence-based treatments of depression remains sketchy at best. In this context, the growing evidence for the efficacy and effectiveness of LTPT is promising. Overall, it is clear that the future of the treatment of depression may lie in a combined disorder- and person-centered, tailored-made approach, which takes into account, particularly in chronic depression, the broader interpersonal context and life history of the individual. It is clear that psychodynamic therapies have an important role to play in this respect. PMID:22370494

Luyten, Patrick; Blatt, Sidney J

2012-03-01

261

Aquaporin-Mediated Improvement of Freeze Tolerance of Saccharomyces cerevisiae Is Restricted to Rapid Freezing Conditions  

PubMed Central

Previous observations that aquaporin overexpression increases the freeze tolerance of baker's yeast (Saccharomyces cerevisiae) without negatively affecting the growth or fermentation characteristics held promise for the development of commercial baker's yeast strains used in frozen dough applications. In this study we found that overexpression of the aquaporin-encoding genes AQY1-1 and AQY2-1 improves the freeze tolerance of industrial strain AT25, but only in small doughs under laboratory conditions and not in large doughs under industrial conditions. We found that the difference in the freezing rate is apparently responsible for the difference in the results. We tested six different cooling rates and found that at high cooling rates aquaporin overexpression significantly improved the survival of yeast cells, while at low cooling rates there was no significant effect. Differences in the cultivation conditions and in the thawing rate did not influence the freeze tolerance under the conditions tested. Survival after freezing is determined mainly by two factors, cellular dehydration and intracellular ice crystal formation, which depend in an inverse manner on the cooling velocity. In accordance with this so-called two-factor hypothesis of freezing injury, we suggest that water permeability is limiting, and therefore that aquaporin function is advantageous, only under rapid freezing conditions. If this hypothesis is correct, then aquaporin overexpression is not expected to affect the leavening capacity of yeast cells in large, industrial frozen doughs, which do not freeze rapidly. Our results imply that aquaporin-overexpressing strains have less potential for use in frozen doughs than originally thought. PMID:15184134

Tanghe, An; Van Dijck, Patrick; Colavizza, Didier; Thevelein, Johan M.

2004-01-01

262

Exact theory of freeze out  

E-print Network

We show that the standard theory of thermal production and chemical decoupling of WIMPs is incomplete. The hypothesis that WIMPs are produced and decouple from a thermal bath implies that the rate equation the bath particles interacting with the WIMPs is an algebraic equation that constraints the actual WIMPs abundance to have a precise analytical form down to the temperature $x_\\ast=m_\\chi /T_\\ast$. The point $x_\\ast$, which coincides with the stationary point of the equation for the quantity $\\Delta= Y-Y_0$, is where the maximum departure of the WIMPs abundance $Y$ from the thermal value $Y_0$ is reached. For each mass $m_\\chi$ and total annihilation cross section $\\langle \\sigma_\\text{ann}v_\\text{r}\\rangle$, the temperature $x_\\ast$ and the actual WIMPs abundance $Y(x_\\ast)$ are exactly known. This value provides the true initial condition for the usual differential equation that have to be integrated in the interval $x\\ge x_\\ast$. The matching of the two abundances $x_\\ast$ is continuous and differentiable. The dependence of the present relic abundance on the abundance at an intermediate temperature is an exact result. The exact theory suggests a new analytical approximation that furnishes the relic abundance accurate at the level of $1\\%-2\\%$ in the case of $S$-wave and $P$-wave scattering cross sections. We conclude te paper studying evolution of the WIMPs chemical potential and the entropy production using methods of non equilibrium thermodynamics.

Mirco Cannoni

2014-07-15

263

[Depression in the elderly].  

PubMed

The incidence of depression is higher than that of dementia in the elderly. Unlike depression in other age groups, that in the elderly is characterized by frequent physical complaints, irritation, and delusional tendencies. The treatment of depression in the elderly requires the complex incorporation of psychiatric and gerontological viewpoints. Psychiatrically, difficulty in accepting decreases in psychological and physical functions and solitude is important, as a psychological characteristic, inducing the development of depression. Biochemically, there is an underlying decrease in the function of brain monoaminergic nerve activated, such as by serotonin and noradrenalin. Radiologically, damage to the cerebral white matter and a decrease in the frontal lobe function have been frequently reported. Depression is difficult to differentiate from dementia and is also often complicated by dementia. Since a depressive state often precede Alzheimer's disease, evaluation of cognitive function is also necessary in patients with a depressive state. Although apathy is often observed as a symptom of dementia and tends to be confused with a depressive symptom, caution is necessary because of differences in the treatment method. Gerontologically, depression is one of geriatric syndrome and isa frequently observed in the elderly in the later stage and closely associated with a decrease in activities of daily life. Depression is also closely associated with lifestyle-related diseases, and its incidence is high in the presence of cerebrovascular disease, ischemic heart disease, hypertension, and diabetes mellitus, and conversely, depression is often complicated by lifestyle-related disease. Anxiety and depression are frequently observed in the frail elderly, but few studies on the assessment and appropriate approach for psychological matters. Further studies are necessary. The treatment of depression in the elderly could be classified into 3 stages. In the acute stage, the treatment method is the same as that in other age groups, mainly consisting of physical and psychological rest and medication. The drug of first choice is a selective serotonin re-uptake inhibitors (SSRI). In intractable cases, electroconvulsive therapy (ECT) is recommended. In the chronic stage, the prevention of disuse syndrome is necessary, and activating approaches such as exercise therapy are used. In addition, support for patients with decreased activities of daily living and the establishment of a community-based cooperation system for the prevention of suicides are future areas to be tackled. It is important that concomitant dementia and physical illness are appropriately assessed and treated in all stages. PMID:19068544

Hattori, Hideyuki

2008-09-01

264

Interspecific analysis of xylem freezing responses in Acer and Betula  

Technology Transfer Automated Retrieval System (TEKTRAN)

Temperate woody plants have evolved two methods for coping with seasonal exposure to sub-zero temperatures. Supercooling is a freeze-avoidance strategy where cells are able to resist the freezing of intracellular water below sub-zero temperatures. Non-supercooling is a freeze-tolerance strategy wh...

265

VISUALIZATION OF FREEZING PROGRESSION IN TURFGRASSES USING INFRARED VIDEO THERMOGRAPHY  

Technology Transfer Automated Retrieval System (TEKTRAN)

Freezing injury can be a significant problem in turfgrasses. Understanding how freezing develops and ramifies throughout the plant could assist in the development of improved management or screening processes for cultivar improvemen. The development of freezing injury is not well understand due pa...

266

Cryomechanical freezing. A model for the heat transfer process  

Microsoft Academic Search

Cryomechanical freezing consists of a two-step process. During the first step, the foodstuff gets into contact with a cryogenic refrigerant for a very short period of time, during which a thin frozen crust is formed. Immediately afterwards, freezing is completed in a conventional cold air-blast freezer. In this work, the heat transfer process during cryomechanical freezing was modelled using the

Miriam E Agnelli; Rodolfo H Mascheroni

2001-01-01

267

Modification of physical properties of freeze-dried rice  

NASA Technical Reports Server (NTRS)

Freeze cycling process consists of alternately freezing and thawing precooked rice for two cycles, rice is then frozen and freeze-dehydrated in vacuum sufficient to remove water from rice by sublimitation. Process modifies rice grain structure and porosity, enabling complete rehydration in one minute in hot water.

Huber, C. S.

1971-01-01

268

Cryomicroscopic analysis of freezing in liver of the freeze-tolerant wood frog.  

PubMed

The technique of directional solidification coupled with low-temperature scanning electron microscopy was applied to analyze the freezing of liver slices from the freeze-tolerant frog Rana sylvatica. Micrographs of liver slices from 5 degrees C-acclimated frogs frozen on the directional stage to -7 degrees C showed continuous ice formed along an expanded vasculature with hepatocytes that were shrunken and virtually dehydrated. However, when frogs were given a survivable freezing exposure at -4 degrees C for 24 h, liver slices subsequently frozen in vitro at -7 degrees C were much less shrunken and the presence of intracellular ice crystals (formed when samples were plunged into liquid N2 before microscopy) demonstrated that ample free water remained in these hepatocytes at -7 degrees C. This reduced level of cell dehydration was correlated with the buildup of 280 +/- 61 mumol/g wet wt glucose as a cryoprotectant in liver during the -4 degrees C exposure in vivo. The study provides the first direct cytological analysis of the freezing process in an organ of a freeze-tolerant vertebrate and the first confirmation of the relationship between maintenance of a critical minimum cell volume and freezing survival by these animals. PMID:1636785

Storey, K B; Bischof, J; Rubinsky, B

1992-07-01

269

Hopelessness Depression: A Theory-Based Subtype of Depression  

Microsoft Academic Search

We present a revision of the 1978 reformulated theory of helplessness and depression and call it the hopelessness theory of depression. Although the 1978 reformulation has generated a vast amount of empirical work on depression over the past 10 years and recently has been evaluated as a model of depression, we do not think that it presents a clearly articulated

Lyn Y. Abramson; Gerald I. Metalsky; Lauren B. Alloy

1989-01-01

270

Predictors of depression stigma  

PubMed Central

Background To investigate and compare the predictors of personal and perceived stigma associated with depression. Method Three samples were surveyed to investigate the predictors: a national sample of 1,001 Australian adults; a local community sample of 5,572 residents of the Australian Capital Territory and Queanbeyan aged 18 to 50 years; and a psychologically distressed subset (n = 487) of the latter sample. Personal and Perceived Stigma were measured using the two subscales of the Depression Stigma Scale. Potential predictors included demographic variables (age, gender, education, country of birth, remoteness of residence), psychological distress, awareness of Australia's national depression initiative beyondblue, depression literacy and level of exposure to depression. Not all predictors were used for all samples. Results Personal stigma was consistently higher among men, those with less education and those born overseas. It was also associated with greater current psychological distress, lower prior contact with depression, not having heard of a national awareness raising initiative, and lower depression literacy. These findings differed from those for perceived stigma except for psychological distress which was associated with both higher personal and higher perceived stigma. Remoteness of residence was not associated with either type of stigma. Conclusion The findings highlight the importance of treating the concepts of personal and perceived stigma separately in designing measures of stigma, in interpreting the pattern of findings in studies of the predictors of stigma, and in designing, interpreting the impact of and disseminating interventions for stigma. PMID:18423003

Griffiths, Kathleen M; Christensen, Helen; Jorm, Anthony F

2008-01-01

271

Depression in Older Adults  

PubMed Central

Depression is less prevalent among older adults than among younger adults but can have serious consequences. Over half of cases represent a first onset in later life. Although suicide rates in the elderly are declining, they are still higher than in younger adults and more closely associated with depression. Depressed older adults are less likely to endorse affective symptoms and more likely to display cognitive changes, somatic symptoms, and loss of interest than are younger adults. Risk factors leading to the development of late life depression likely comprise complex interactions among genetic vulnerabilities, cognitive diathesis, age-associated neurobiological changes, and stressful events. Insomnia is an often overlooked risk factor for late life depression. We suggest that a common pathway to depression in older adults, regardless of which predisposing risks are most prominent, may be curtailment of daily activities. Accompanying self-critical thinking may exacerbate and maintain a depressed state. Offsetting the increasing prevalence of certain risk factors in late life are age-related increases in psychological resilience. Other protective factors include higher education and socioeconomic status, engagement in valued activities, and religious or spiritual involvement. Treatments including behavioral therapy, cognitive behavioral therapy, cognitive bibliotherapy, problem-solving therapy, brief psychodynamic therapy, and life review/reminiscence therapy are effective but too infrequently used with older adults. Preventive interventions including education for individuals with chronic illness, behavioral activation, cognitive restructuring, problem-solving skills training, group support, and life review have also received support. PMID:19327033

Fiske, Amy; Wetherell, Julie Loebach; Gatz, Margaret

2010-01-01

272

Post Stroke Depression  

PubMed Central

ABSTRACT Introduction: Comorbidity of depression and stroke significantly reduces the quality of life of patients after the stroke. Squeal after stroke also determines the quality of life and have impact on the occurrence of depression after the stroke. In our study we investigated the occurrence of depression in patients after different types and subtypes of stroke measured by the Hamilton scale compared to the level of disability measured by NIHSS scale. Goal: The goal was to make a comparative analysis of depression after stroke, according to gender and age, side of the lesion and the severity of neurological deficit. Material and Methods: Material for our work are 210 patients with stroke treated at the Neurology Clinic, Clinical Center of Sarajevo University in 2012, 105 male and 105 female. The mean age of the patients was 67.12±9.5 years. Ischemic stroke was present in 65% cases. There was no statistically significant difference between ischemic and hemorrhagic stroke among genders. In case of hemorrhagic M-56.7%, F-43.3%; ischemic M-48.3%, F-51.7% (chi-square=6.563, p=0.082). Depression was more prevalent among younger patients (52-60 years) with 39.2% then in the group of older patients (61-70 years) with 32% of depressed. In relation to gender there was significantly more patients with depression among women compared to men (63.8:27.2%, chi-square=14.38, p=0.00019). Depression was more frequent in patients with stroke in the left hemisphere medial localization (63%). NIHSS scale average was 16.07 with the minimum of 11 and maximum of 22, F=52.56, p=0.001. Conclusions: We can conclude that depression after stroke is more frequent in younger patients, female patients, patients with localized stroke in the medial left hemisphere and with higher disability score. PMID:24783913

Alajbegovic, Azra; Djelilovic-Vranic, Jasminka; Alajbegovic, Salem; Nakicevic, Amina; Todorovic, Ljubica; Tiric-Campara, Merita

2014-01-01

273

Management of Postpartum Depression  

PubMed Central

Postpartum depression, now termed peripartum depression by the DSM-V, is one of the most common complications in the postpartum period and has potentially significant negative consequences for mothers and their families. This article highlights common clinical challenges in the treatment of peripartum depression and reviews the evidence for currently available treatment options. Psychotherapy is the first-line treatment options for women with mild-to-moderate peripartum depression. Antidepressant medication in combination with therapy is recommended for women with moderate-to-severe depression. While pooled case reports and small controlled studies have demonstrated undetectable infant serum levels and no short-term adverse events in infants of mothers breastfeeding while taking sertraline (Zoloft) and paroxetine (Paxil), further research is needed including larger samples and long-term follow-up of infants exposed to antidepressants via breastfeeding with control for maternal depression. Pharmacological treatment recommendations in women who are lactating must include discussion with the patient regarding the benefits of breastfeeding, risks of antidepressant use during lactation and risks of untreated illness. There is a growing evidence base for non-pharmacological interventions including repetitive Transcranial Magnetic Stimulation (rTMS) which may offer an attractive option for women who wish to continue to breastfeed and are concerned about exposure of medication to their infant. Among severe cases of peripartum depression with psychosis referral to a psychiatrist or psychiatric APRN is warranted. Suicidal or homicidal ideation with a desire, intent or plan to harm oneself or anyone one else, including the infant, is a psychiatric emergency, and an evaluation by a mental health professional should be conducted immediately. Peripartum depression treatment research is limited by small samples sizes and few controlled studies. Much work is still needed to better understand which treatments women prefer and are the most effective in ameliorating the symptoms and disease burden associated with peripartum depression. PMID:24131708

Guille, Constance; Newman, Roger; Fryml, Leah D.; Lifton, Clay K.; Epperson, C. Neill

2013-01-01

274

Spacecraft Radiator Freeze Protection Using a Regenerative Heat Exchanger  

NASA Technical Reports Server (NTRS)

An active thermal control system architecture has been modified to include a regenerative heat exchanger (regenerator) inboard of the radiator. Rather than using a radiator bypass valve a regenerative heat exchanger is placed inboard of the radiators. A regenerator cold side bypass valve is used to set the return temperature. During operation, the regenerator bypass flow is varied, mixing cold radiator return fluid and warm regenerator outlet fluid to maintain the system setpoint. At the lowest heat load for stable operation, the bypass flow is closed off, sending all of the flow through the regenerator. This lowers the radiator inlet temperature well below the system set-point while maintaining full flow through the radiators. By using a regenerator bypass flow control to maintain system setpoint, the required minimum heat load to avoid radiator freezing can be reduced by more than half compared to a radiator bypass system.

Ungar, Eugene K.; Schunk, Richard G.

2011-01-01

275

Hippocampal volume in geriatric depression  

Microsoft Academic Search

Background: There is a growing literature on the importance of hippocampal volume in geriatric depression.Methods: We examined hippocampal volume in a group of elderly depressed patients and a group of elderly control subjects (N = 66 geriatric depressed patients and 18 elderly nondepressed control subjects) recruited through Duke’s Mental Health Clinical Research Center for the Study of Depression in the

David C Steffens; Christopher E Byrum; Douglas R McQuoid; Daniel L Greenberg; Martha E Payne; Timothy F Blitchington; James R MacFall; K. Ranga Rama Krishnan

2000-01-01

276

Depression, Pain, and Pain Behavior.  

ERIC Educational Resources Information Center

Examined the degree to which depression predicted pain and pain behavior. The Beck Depression Inventory was administered to 207 low back pain patients. Depression and physical findings were the most important predictors of pain and pain behavior. Depression proved significant even after controlling for important demographic and medical status…

Keefe, Francis J.; And Others

1986-01-01

277

Depression and Pregnancy  

MedlinePLUS

... miscarriage, low birth weight, and babies who are small-for-gestational age when depression is left untreated in pregnancy. Pre- ... pregnancy and the risk of preterm birth, low birth weight, and intrauterine growth restriction. Arch Gen Psychiatry 67( ...

278

Depression in the Workplace  

MedlinePLUS

... as heart disease or AIDS to the US economy, costing over $51 billion in absenteeism from work ... on treatment for heart disease iv . The annual economic cost of depression in 1995 was $600 per ...

279

Learning about depression  

MedlinePLUS

Fava M, Cassano P. Mood disorders: Major depressive disorder and dysthymic disorder. In: Stern TA, Rosenbaum JF, Fava M, Biederman J, Rauch SL, eds. Massachusetts General Hospital Comprehensive Clinical Psychiatry . 1st ed. ...

280

Depression, Dementia, and Delirium  

Microsoft Academic Search

Upon completion of the chapter, the student will be able to:\\u000a \\u000a \\u000a \\u000a 1. \\u000a \\u000a State the epidemiology of depression, dementia, and delirium in older adults.\\u000a \\u000a \\u000a \\u000a \\u000a 2. \\u000a \\u000a Describe the risk factors for the development of depression, dementia, and delirium.\\u000a \\u000a \\u000a \\u000a \\u000a 3. \\u000a \\u000a Understand the diagnostic workup of depression, dementia, and delirium.\\u000a \\u000a \\u000a \\u000a \\u000a 4. \\u000a \\u000a Develop a rational management plan for persons with depression, dementia, or delirium.

Rainier P. Soriano

281

[Depression and circadian rhythm].  

PubMed

Adverse changes in circadian rhythms are an integral part of the clinical features of endogenous depression, and particularly of seasonal depression. Alongside twenty-four variations in the major symptoms, these forms of depression can be characterised psychometrically, physiologically and biologically. The most classical adverse changes are amplitude modifications, fluctuations and periodicity of the hormonal secretory rhythms. Pathophysiological and psychopathological models have been proposed to combat these abnormalities. The leading models include free course, phase advance (or instability) and hypnic models, or those based on disturbances of the internal clock. The main psychopathological models are those of endokinesis and psychosocial desynchronisation. The therapeutic applications of the pathophysiological models use manipulation of the wake-sleep cycle, phototherapy and melatonin and its derivatives : those of the psychopathological models used time-space management and development of resynchronisation capacities. The question determining whether these adverse changes are a cause or effect of depressive behaviour is unresolved. PMID:19268174

Azorin, J M; Kaladjian, A

2009-01-01

282

Freeze-out parameters: lattice meets experiment.  

PubMed

We present our results for ratios of higher order fluctuations of electric charge as functions of the temperature. These results are obtained in a system of 2+1 quark flavors at physical quark masses and continuum extrapolated. We compare them to preliminary data on higher order moments of the net electric charge distribution from the STAR collaboration. This allows us to determine the freeze-out temperature and chemical potential from first principles. We also show continuum-extrapolated results for ratios of higher order fluctuations of baryon number. These will allow us to test the consistency of the approach, by comparing them to the corresponding experimental data (once they become available) and thus, extracting the freeze-out parameters in an independent way. PMID:23971565

Borsányi, S; Fodor, Z; Katz, S D; Krieg, S; Ratti, C; Szabó, K K

2013-08-01

283

The Effect of Parkinson Drug Timing on Cardiovascular Response during Treadmill Exercise in a Person with Parkinson Disease and Freezing of Gait  

PubMed Central

ABSTRACT Purpose: To examine the response of cerebral oxygenation during treadmill walking in a person with Parkinson disease (PD) who experiences freezing of gait (FOG) and to determine whether the oxygen response was related to the timing of his PD medication. Client Description: A 61-year-old man with PD performed two bouts of treadmill testing on the same day, during the on- and off-phases of his PD medication. Measures and Outcome: The client experienced two FOG episodes during the first testing session (on-phase with hypokinetic movement session). Cerebral oxygen response (measured by near-infrared spectroscopy) was stable until the FOG episodes occurred, at which point it decreased until the FOG episode was over. No electrocardiogram (ECG) changes or lightheadedness were noted; blood pressure (BP) remained stable. During the second exercise testing session (off-phase with dyskinetic movement session), the client did not experience any FOG episodes, and his cerebral oxygen response remained stable. Toward the end of the second testing session, he experienced lightheadedness and a drop in BP of approximately 30 mmHg, along with significant ST segment depression on his ECG. Implications: Haemodynamic and cerebral oxygen changes occurred that were specific to the timing of the client's PD medication and to his FOG episodes. This case study shows a person with PD demonstrating decreased cerebral oxygenation during FOG, which may be based on his variable response to levodopa medication or may be attributable to as yet unidentified physiologic mechanisms. PMID:24403689

Nelson, Reid; Steffen, Teresa M.

2013-01-01

284

Kinetic density functional theory of freezing  

NASA Astrophysics Data System (ADS)

A theory of freezing of a dense hard sphere gas is presented. Starting from a revised Enskog theory, hydrodynamic equations that account for non-local variations in the density but local variations in the flow field are derived using a modified Chapman Enskog procedure. These hydrodynamic equations, which retain structural correlations, are shown to be effectively a time dependent density functional theory. The ability of this theory to capture the solid liquid phase transition is established through analysis and numerical simulations.

Baskaran, Arvind; Baskaran, Aparna; Lowengrub, John

2014-11-01

285

Hadron Freeze-out and QGP Hadronization  

Microsoft Academic Search

Abundances and $m_\\\\bot$-spectra of strange and other hadronic particles emanating from central 158-200 A GeV reactions between nuclei are found to originate from a thermally equilibrated, deconfined source in chemical non-equilibrium. Physical freeze-out parameters and physical conditions (pressure, specific energy, entropy, and strangeness) are evaluated. Five properties of the source we obtain are as expected for direct hadron emission (hadronization)

Johann Rafelski; Jean Letessier

1999-01-01

286

Freeze-branding to permanently mark bats  

Microsoft Academic Search

We tested the effectiveness of freeze-branding as a permanent marking technique on 4 species of bats: Brazilian free-tailed bat (Tadarida brasiliensis), Townsend's big-eared bat (Corynorhinus townsendil), big brown bat (Eptesicus fuscus), and western small-footed myotis (Myotis ciliolabrum). Small copper branding irons (9.3 g and 15.6 g) were cooled in a mixture of dry ice and ethyl alcohol and applied to

Richard E. Sherwin; Shauna Haymond; Rebeccah Olsen

287

Emerging from Depression: Treatment of Adolescent Depression Using the Major Treatment Models of Adult Depression.  

ERIC Educational Resources Information Center

Noting that adolescents who commit suicide are often clinically depressed, this paper examines various approaches in the treatment of depression. Major treatment models of adult depression, which can be directly applied to the treatment of the depressed adolescent, are described. Major treatment models and selected research studies are reviewed in…

Long, Kathleen M.

288

Disaggregating meteorites by automated freeze thaw  

NASA Astrophysics Data System (ADS)

An automated freeze-thaw (AFT) instrument for disaggregating meteorites is described. Meteorite samples are immersed in 18.2 M? water and hermetically sealed in a clean 30 ml Teflon vial. This vial and its contents are dipped between baths of liquid nitrogen and hot water over a number of cycles by a dual-stepper motor system controlled by LabView. Uniform and periodic intervals of freezing and thawing induce multiple expansions and contractions, such that cracks propagate along natural flaws in the meteorite for a sufficient number of AFT cycles. For the CR2 chondrite NWA801, the boundaries between different phases (i.e., silicates, metal, matrix) became progressively weaker and allowed for an efficient recovery of 500 individual chondrules and chondrule fragments spanning 0.2-4.7 mm diameters after 243 AFT cycles over 103.3 h. Further FT experiments on a basalt analog showed that the time required for freezing and thawing the same number of cycles can be reduced by a factor of ˜4.

Charles, Christopher R. J.

2011-06-01

289

Disaggregating meteorites by automated freeze thaw.  

PubMed

An automated freeze-thaw (AFT) instrument for disaggregating meteorites is described. Meteorite samples are immersed in 18.2 M? water and hermetically sealed in a clean 30 ml Teflon vial. This vial and its contents are dipped between baths of liquid nitrogen and hot water over a number of cycles by a dual-stepper motor system controlled by LabView. Uniform and periodic intervals of freezing and thawing induce multiple expansions and contractions, such that cracks propagate along natural flaws in the meteorite for a sufficient number of AFT cycles. For the CR2 chondrite NWA801, the boundaries between different phases (i.e., silicates, metal, matrix) became progressively weaker and allowed for an efficient recovery of 500 individual chondrules and chondrule fragments spanning 0.2-4.7 mm diameters after 243 AFT cycles over 103.3 h. Further FT experiments on a basalt analog showed that the time required for freezing and thawing the same number of cycles can be reduced by a factor of ?4. PMID:21721725

Charles, Christopher R J

2011-06-01

290

Atmospheric freeze drying assisted by power ultrasound  

NASA Astrophysics Data System (ADS)

Atmospheric freeze drying (AFD) is considered an alternative to vacuum freeze drying to keep the quality of fresh product. AFD allows continuous drying reducing fix and operating costs, but presents, as main disadvantage, a long drying time required. The application of power ultrasound (US) can accelerate AFD process. The main objective of the present study was to evaluate the application of power ultrasound to improve atmospheric freeze drying of carrot. For that purpose, AFD experiments were carried out with carrot cubes (10 mm side) at constant air velocity (2 ms-1), temperature (-10°C) and relative humidity (10%) with (20.5 kWm-3,USAFD) and without (AFD) ultrasonic application. A diffusion model was used in order to quantify the influence of US in drying kinetics. To evaluate the quality of dry products, rehydration capacity and textural properties were determined. The US application during AFD of carrot involved the increase of drying rate. The effective moisture diffusivity identified in USAFD was 73% higher than in AFD experiments. On the other hand, the rehydration capacity was higher in USAFD than in AFD and the hardness of dried samples did not show significant (p<0.05) differences. Therefore, US application during AFD significantly (p<0.05) sped-up the drying process preserving the quality properties of the dry product.

Santacatalina, J. V.; Cárcel, J. A.; Simal, S.; Garcia-Perez, J. V.; Mulet, A.

2012-12-01

291

Aquaporin Expression Correlates with Freeze Tolerance in Baker's Yeast, and Overexpression Improves Freeze Tolerance in Industrial Strains  

PubMed Central

Little information is available about the precise mechanisms and determinants of freeze resistance in baker's yeast, Saccharomyces cerevisiae. Genomewide gene expression analysis and Northern analysis of different freeze-resistant and freeze-sensitive strains have now revealed a correlation between freeze resistance and the aquaporin genes AQY1 and AQY2. Deletion of these genes in a laboratory strain rendered yeast cells more sensitive to freezing, while overexpression of the respective genes, as well as heterologous expression of the human aquaporin gene hAQP1, improved freeze tolerance. These findings support a role for plasma membrane water transport activity in determination of freeze tolerance in yeast. This appears to be the first clear physiological function identified for microbial aquaporins. We suggest that a rapid, osmotically driven efflux of water during the freezing process reduces intracellular ice crystal formation and resulting cell damage. Aquaporin overexpression also improved maintenance of the viability of industrial yeast strains, both in cell suspensions and in small doughs stored frozen or submitted to freeze-thaw cycles. Furthermore, an aquaporin overexpression transformant could be selected based on its improved freeze-thaw resistance without the need for a selectable marker gene. Since aquaporin overexpression does not seem to affect the growth and fermentation characteristics of yeast, these results open new perspectives for the successful development of freeze-resistant baker's yeast strains for use in frozen dough applications. PMID:12450819

Tanghe, An; Van Dijck, Patrick; Dumortier, Françoise; Teunissen, Aloys; Hohmann, Stefan; Thevelein, Johan M.

2002-01-01

292

Management of postpartum depression.  

PubMed

The mainstays of treatment for peripartum depression are psychotherapy and antidepressant medications. More research is needed to understand which treatments are safe, preferable, and effective. Postpartum depression, now termed peripartum depression by the DSM-V, is one of the most common complications in the postpartum period and has potentially significant negative consequences for mothers and their families. This article highlights common clinical challenges in the treatment of peripartum depression and reviews the evidence for currently available treatment options. Psychotherapy is the first-line treatment option for women with mild to moderate peripartum depression. Antidepressant medication in combination with therapy is recommended for women with moderate to severe depression. Although pooled case reports and small controlled studies have demonstrated undetectable infant serum levels and no short-term adverse events in infants of mothers breastfeeding while taking sertraline (Zoloft) and paroxetine (Paxil), further research is needed including larger samples and long-term follow-up of infants exposed to antidepressants via breastfeeding controlling for maternal depression. Pharmacologic treatment recommendations for women who are lactating must include discussion with the patient regarding the benefits of breastfeeding, risks of antidepressant use during lactation, and risks of untreated illness. There is a growing evidence base for nonpharmacologic interventions including repetitive transcranial magnetic stimulation, which may offer an attractive option for women who wish to continue to breastfeed and are concerned about their infants being exposed to medication. Among severe cases of peripartum depression with psychosis, referral to a psychiatrist or psychiatric advanced practice registered nurse is warranted. Suicidal or homicidal ideation with a desire, intent, or plan to harm oneself or anyone else, including the infant, is a psychiatric emergency, and an evaluation by a mental health professional should be conducted immediately. Peripartum depression treatment research is limited by small sample sizes and few controlled studies. Much work is still needed to better understand which treatments women prefer and are the most effective in ameliorating the symptoms and disease burden associated with peripartum depression. PMID:24131708

Guille, Constance; Newman, Roger; Fryml, Leah D; Lifton, Clay K; Epperson, C Neill

2013-01-01

293

Treatment of self-reported depression among Hispanics and African Americans.  

PubMed

This study applied the Behavioral Model for Vulnerable Populations framework to examine the correlates of depression and the receipt of medical treatment among low-income Hispanics and African Americans residing in public housing. We compared three groups: those who reported (1) self-diagnosed but without physician-diagnosed depression, (2) depression diagnosed by a physician but who did not receive pharmaceutical treatment, and (3) depression diagnosed by a physician and antidepressant pharmacotherapy consumed by patient. Random samples of 287 adults from three public housing communities were surveyed. Over 48% of this sample reported that they were suffering from depression. One out of three people who reported being depressed also said that a physician had never diagnosed his or her condition. Only 40% of those who said that a physician had diagnosed depression also reported taking antidepressant medication. Untreated depression among underserved racial and ethnic minorities is alarming and points to an urgent need for intervention. PMID:15937396

Bazargan, Mohsen; Bazargan-Hejazi, Shahrzad; Baker, Richard S

2005-05-01

294

Sexual Minority Status, Peer Harassment, and Adolescent Depression  

PubMed Central

The well-documented higher rates of depression among sexual minority youth are increasingly viewed by developmentalists as a byproduct of the stigmatization of sexual minority status in American society and of the negative impact this stigma has on the processes associated with depression. This study attempted to spur future research by testing Hatzenbuehler’s (2009) psychological mediation framework to investigate the ways in which peer harassment related to sexuality puts young people at risk by influencing the cognitive, social, and regulatory factors associated with depression. Analyses of 15 year olds in the NICHD Study of Early Child Care and Youth Development revealed that sexual minority status was largely associated with depressive outcomes via harassment, which was subsequently associated with depression via cognitive and social factors. Results point to various avenues for exploring the importance of the social world and self-concept for the outcomes of sexual minority adolescents in the future. PMID:22401842

Martin-Storey, Alexa; Crosnoe, Robert

2012-01-01

295

Lifestyle medicine for depression  

PubMed Central

The prevalence of depression appears to have increased over the past three decades. While this may be an artefact of diagnostic practices, it is likely that there are factors about modernity that are contributing to this rise. There is now compelling evidence that a range of lifestyle factors are involved in the pathogenesis of depression. Many of these factors can potentially be modified, yet they receive little consideration in the contemporary treatment of depression, where medication and psychological intervention remain the first line treatments. “Lifestyle Medicine” provides a nexus between public health promotion and clinical treatments, involving the application of environmental, behavioural, and psychological principles to enhance physical and mental wellbeing. This may also provide opportunities for general health promotion and potential prevention of depression. In this paper we provide a narrative discussion of the major components of Lifestyle Medicine, consisting of the evidence-based adoption of physical activity or exercise, dietary modification, adequate relaxation/sleep and social interaction, use of mindfulness-based meditation techniques, and the reduction of recreational substances such as nicotine, drugs, and alcohol. We also discuss other potential lifestyle factors that have a more nascent evidence base, such as environmental issues (e.g. urbanisation, and exposure to air, water, noise, and chemical pollution), and the increasing human interface with technology. Clinical considerations are also outlined. While data supports that some of these individual elements are modifiers of overall mental health, and in many cases depression, rigorous research needs to address the long-term application of Lifestyle Medicine for depression prevention and management. Critically, studies exploring lifestyle modification involving multiple lifestyle elements are needed. While the judicious use of medication and psychological techniques are still advocated, due to the complexity of human illness/wellbeing, the emerging evidence encourages a more integrative approach for depression, and an acknowledgment that lifestyle modification should be a routine part of treatment and preventative efforts. PMID:24721040

2014-01-01

296

Analysis of a proposed fuel freezing mechanism in a rod bundle  

E-print Network

mechanism. It may be that molten steel entrained into the fuel flow will lower the leading edge temperature until a point. at which instantaneous wall melting no longer occurs. Then the leading edge will deposit on the channel walls a layer of stable... A. Erdman A proposed fuel freezing mechanism for molten U02 fuel penetrating a steel channel was investigated in the course of liquid-metal-cooled fast breeder reactor hypothetical core disruptive accident safety studies. The fuel crust...

Nguyen-Wayne, David Loc

1983-01-01

297

Variation of the average 'freezing-in' temperature of oxygen ions with solar wind speed  

NASA Technical Reports Server (NTRS)

Observations of the average oxygen ionization equilibrium as a function of speed of the solar wind are presented. At low solar wind speeds they indicate a coronal temperature at the freezing-in point of (1.6 + or - 0.2) x 10 to the 6th K. At speeds above 450 km/sec the apparent temperature starts to rise rapidly. This rise is tentatively interpreted in terms of a lack of thermodynamic equilibrium in the source region.

Ogilvie, K. W.; Vogt, C.

1980-01-01

298

Evidence for a role of raffinose in stabilizing photosystem II during freeze–thaw cycles  

Microsoft Academic Search

A role of non-reducing sugars like sucrose and raffinose in the protection of plant cells against damage during freezing has\\u000a been proposed for many species, but reports on physiological effects are conflicting. Non-aqueous fractionation of mesophyll\\u000a cell compartments in Arabidopsis thaliana was used to show that sucrose and raffinose accumulate in plastids during low temperatures, pointing to a physiological role

Markus Knaupp; Kumud B. Mishra; Ladislav Nedbal; Arnd G. Heyer

299

Agomelatine, melatonin and depressive disorder.  

PubMed

Alteration of nocturnal melatonin production, along with circadian rhythm disturbance, has been demonstrated in several psychiatric disorders. It has been postulated that such disturbances might be causal reflecting a more fundamental abnormality of the function of the suprachiasmatic nucleus (SCN). The SCN contains the body's master 'clock' while the pineal-SCN nexus is intricate to the nighttime production of melatonin. The more compelling case for causality is made for major depressive disorder (MDD). Lending weight to this proposition is the introduction of agomelatine as an antidepressant agent. Through its actions on melatonin receptors agomelatine can resynchronise circadian rhythms. The circadian hypothesis would posit that normalisation of disturbance would be sufficient of itself to alleviate the symptoms of MDD. Thus, strategies designed to bring about resynchronisation of circadian rhythms should be therapeutically effective in depression. Critical examination of the efficacy of such interventions in MDD suggests that the circadian alteration may be necessary but is not sufficient for an antidepressant effect. Exogenous melatonin administration and bright light therapy have mixed results in limited controlled clinical evaluations. Furthermore, agomelatine has other actions which pre-clinical studies suggest are as important to its therapeutic effects as are its actions on melatonin receptors ipso facto its resynchronising properties. Whether circadian effects are antidepressant remains a moot point and awaits the clinical evaluation of highly selective resynchronising agents. PMID:23484857

Norman, Trevor R

2013-04-01

300

[Depression in general practitioner].  

PubMed

Identification of Major Depressive Disorder (MDD) can be easily done by asking systematically the following questions. During the last month: "Did you lose interest and pleasure for the things that you usually like and enjoy?" "Have you lost energy, or do you feel abnormally tired or depressed?" Physical symptoms of MDD are more frequent for patients supported by general practitioner. Patients suffering from a general medical affection are more likely to present a risk of MDD. Treatment of MDD for patients suffering from a general medical affection must be identical to that of patients not suffering from a medical affection. Objective of the antidepressant treatment is the complete remission and not only the response. Evaluating precisely the symptoms of depression in pretherapetical phase allows to facilitate distinction of side effects of a treatment versus residual symptoms of depression. Treatment must be taken during a sufficient period: 6 to 9 months for a first Major depressive episode up to entire life for the most serious cases of recurrent MDD. Making the patient aware of the main side effects of the treatment that he will face rapidly (digestion troubles essentially) is a simple way to reduce the risks of early abandon of the treatment. PMID:23140855

Magalon-Bingenheimer, Katja; Magalon, David; Zendjidjian, Xavier; Boyer, Laurent; Griguer, Ygal; Lançon, Christophe

2013-04-01

301

Depression - The Proteus of Medicine  

PubMed Central

Depression is discussed as a disease of antiquity with suitable contemporary references also. The prevalence of this disorder, which at a given time constitutes 121 millions world-wide is mentioned. Among the types of depression, comorbid depression forms an important one. Classical depression forms the visible part of the depression iceberg while somatic and other life contextual situation forms the submerged part. Somatic manifestations per se do not carry diagnostic weightage unless the core features of depression are elicited. Non-recognition of somatic manifestations result in under-diagnosis and under treatment of the disorder. PMID:21408045

Rao, A. Venkoba

2004-01-01

302

Ni20Cr and 304L stainless steel powders coated with a melting point depressant, Ni 7 UP, were used as the interlayers to produce large root opening 304 stainless steel joints  

Microsoft Academic Search

Powder particles coated with a small amount of melting point de- pressant (MPD) reveal different sintering behavior in comparison to an uncoated powder mixture of the same composi- tion. Interlayers consisting of the coated powder particles were used in the tran- sient liquid-phase (TLP) bonding process. The coating material and the thickness of the deposit are important parameters that influence

W. D. ZHUANG; T. W. EAGAR

303

It's My Life: Depression  

NSDL National Science Digital Library

It's My Life, a PBS Kids Web-based educational series, offers 9-12 year olds a kid-friendly way to explore and share the issues in their lives. Depression is just one of many subjects addressed in It's My Life. Topics covered in this Web site include defining depression, recognizing the symptoms, understanding the causes, getting treatment, how to help a friend or parent who may be suffering from depression, and more. In addition to articles on these topics, the Web site provides interactive activities -- such as a quiz and a chat room -- that help kids further their understanding of the disease and reach out for help if needed. Offline activities include a printable journal page, a recommended reading list, and discussion questions that kids can take to a parent or friend.

2002-01-01

304

Physical symptoms of depression.  

PubMed

The incidence of physical symptoms in depression was studied in 51 drug-free patients and in an age and sex-matched control group. Mean symptom intensity and number of symptoms were significantly higher in the patient than in the control group. The subjects' personality structure and relationships between their symptoms and degrees of depression and anxiety were examined using the Eysenck Personality Inventory (EPI), the Beck Depression Inventory, and the Spielberger State-Trait Anxiety Inventory, respectively. Of the variables studied, only the N score of the EPI was shown to influence the symptoms significantly. The effect of such non-specific factors as age, gender, use of alcohol, coffee, tea, and cigarettes was also evaluated and found to be minimal. PMID:7326538

Mathew, R J; Weinman, M L; Mirabi, M

1981-10-01

305

[A new proposal for the diagnosis of depression].  

PubMed

Depression has a high impact on mental health. However its diagnosis is a challenge even for specialists. This problem derives from a failure in an adequate description and differentiation of the disease. This inadequate conceptualization generates these difficulties. Our thesis is that depression should be understood as a complex phenomenon that can be analyzed from multiple perspectives, from genes to behavior, including personality and interaction with the sociocultural environment. The aim of this paper is to review the psychopathological construct of depression from a multidimensional point of view, considering clinical, sociocultural, characterological and pathogenic variables. Finally we provide a proposal for an adequate diagnostic approach. PMID:25601115

Botto, Alberto; Acuña, Julia; Jiménez, Juan Pablo

2014-10-01

306

Impact of Nucleon Mass Shift on the Freeze Out Process  

E-print Network

The freeze out of a massive nucleon gas through a finite layer with time-like normal is studied. The impact of in-medium nucleon mass shift on the freeze out process is investigated. A considerable modification of the thermodynamical variables temperature, flow-velocity, energy density and particle density has been found. Due to the nucleon mass shift the freeze out particle distribution functions are changed noticeably in comparison with evaluations, which use vacuum nucleon mass.

S. Zschocke; L. P. Csernai; E. Molnar; J. Manninen; A. Nyiri

2005-10-27

307

Strange hadron resonances and QGP freeze-out  

Microsoft Academic Search

We describe how the abundance and distribution of hyperon resonances can be used to probe freeze-out conditions. We demonstrate that resonance yields allow us to measure the time scales of chemical and thermal freeze-outs. This should permit a direct differentiation between the explosive, sudden and staged adiabatic freeze-out scenarios. We then discuss the meaning of recent experimental results and suggest

G. Torrieri; J. Rafelski

2002-01-01

308

The Role of Stressful Life Events in the Development of Depressive Symptoms in Adolescence--A Longitudinal Community Study  

ERIC Educational Resources Information Center

Depressive symptoms were measured in a cohort of community-based adolescents (n=163) at two time-points, with 1 year intervening. At Time 2, participants also answered a scale about past-year stressful life events. Depressive symptoms increased from Time 1 to Time 2, the effect being stronger for girls than for boys. Depressive symptoms were…

Waaktaar, Trine; Borge, Anne Inger Helmen; Fundingsrud, Hans Petter; Christie, Helen Johnsen; Torgersen, Svenn

2004-01-01

309

Freeze Tolerant Radiator for an Advanced EMU  

NASA Technical Reports Server (NTRS)

During an Extravehicular Activity (EVA), the astronaut s metabolic heat and the heat produced by the Portable Life Support Unit (PLSS) must be rejected. This heat load is currently rejected by a sublimator, which vents up to eight pounds of water each EVA. However, for advanced space missions of the future, water venting to space needs to be minimized because resupply impacts from earth will be prohibitive. If this heat load could be radiated to space from the PLSS, which has enough surface area to radiate most of the heat, the amount of water now vented could be greatly reduced. Unfortunately, a radiator rejects heat at a relatively constant rate, but the astronauts generate a variable heat load depending on how hard they are working. Without a way to vary the heat removal rate, the astronaut would experience cold discomfort or even frostbite. A proven method allowing a radiator to be turned-down is to sequentially allow tubes that carry the heat transfer fluid to the radiator to freeze. A drawback of current freezable radiators using this method is that they are far to heavy for use on a PLSS, because they use heavy construction to prevent the tubes from bursting as they freeze and thaw. This creates the need for a large radiator to reject most of the heat but with a lightweight tube that doesn t burst as it freezes and thaws. The new freezable radiator for the Extravehicular Mobility Unit (EMU) has features to accommodate the expansion of the radiator fluid when it freezes, and still have the high tube to fin conductance needed to minimize the number and weight of the tubes. Radiator fluid candidates are water and a propylene glycol-water mixture. This design maintains all materials within their elastic limits so that large volume changes can be achieved without breaking the tube. This concept couples this elastic expansion with an extremely lightweight, extremely high conductivity carbon fiber fin that can carry the heat needed to thaw a frozen tube. By using most of the exposed surface area of the PLSS as a radiator, the system can reject about 75% of the highest heat load, and reduce the loss of water through sublimation by a factor of four. The proposed radiator and a small water tank can be no heavier than the current system.

Copeland, Robert J.; Elliott, Jeannine; Weislogel, Mark

2004-01-01

310

Infrared thermal analysis of plant freezing processes.  

PubMed

Infrared thermal analysis is an invaluable technique to study the plant freezing process. In the differential mode infrared thermal analysis allows to localize ice nucleation and ice propagation in whole plants or plant samples at the tissue level. Ice barriers can be visualized, and supercooling of cells, tissues, and organs can be monitored. Places where ice masses are accommodated in the apoplast can be identified. Here, we describe an experimental setting developed in the laboratory in Innsbruck, give detailed information on the practical procedure and preconditions, and give additionally an idea of the problems that can be encountered and how they by special precautions may be overcome. PMID:24852631

Neuner, Gilbert; Kuprian, Edith

2014-01-01

311

The Ammonia Freeze Explosion (AFEX) process  

SciTech Connect

The Ammonia Freeze Explosion (AFEX) process treats lignocellulose with high-pressure liquid ammonia, and then explosively releases the pressure. The combined chemical effect (cellulose decrystallization) and physical effect (increased accessible surface area) dramatically increase lignocellulose susceptibility to enzymatic attack. There are many adjustable parameters in the AFEX process: ammonia loading, water loading, temperature, time, blowdown pressure, and number of treatments. The effect of these parameters on enzymatic susceptibility was explored for three materials: Coastal bermudagrass, bagasse, and newspaper. Nearly quantitative sugar yields were demonstrated for Coastal bermudagrass and bagasse, using a very low enzyme loading (5 IU/g). Newspaper proved to be much more resistant to enzymatic hydrolysis.

Holtzapple, M.T.; Jae-Hoon Jun; Ganesh Ashok; Patibandla, S.L.; Dale, B.E. [Texas A& M Univ., College Station, TX (United States)

1991-12-31

312

Short versions of the geriatric depression scale: a study of their validity for the diagnosis of a major depressive episode according to ICD10 and DSM-IV  

Microsoft Academic Search

Objective. To determine the validity of short Geriatric Depression Scale (GDS) versions for the detection of a major depressive episode according to ICD-10 criteria for research and DSM-IV. Design. Cross-sectional evaluation of depressive symptoms in a sample of elderly subjects with short GDS versions. DiÄerent GDS cutoÄ points were used to estimate the sensitivity, specificity, positive predictive value and negative

Osvaldo P. Almeida; Shirley A. Almeida

1999-01-01

313

Screening for postpartum depression in an inner-city population  

Microsoft Academic Search

Objective: This study was undertaken to determine the prevalence of positive screens for postpartum depression by using the Edinburgh Postnatal Depression Scale (EPDS) in an inner-city population. Study Design: At their postpartum visits, women who were seen in two inner-city practices between February 20 and April 30, 2002, self-administered the EPDS. A threshold of 10 or more points was selected

Jeanine K. Morris-Rush; Margaret Comerford Freda; Peter S. Bernstein

2003-01-01

314

[Central serous chorioretinitis and depressive disorder - a psychosomatic perspective].  

PubMed

Central serous chorioretinitis serosa is repeatedly brought into aetiological considerations with a rather unspecific concept of distress. Depressive disorder represents a specific stressor, which is known in cardiology or diabetology as a significant risk factor. In the present case report, the clinical correlation between a central serous chorioretinitis and a depressive disorder is shown from a psychosomatic point of view, comparing a sequentially-reactive understanding of the disorder complex with a preferable model of simultaneous entanglement. PMID:24901424

Haisch, S; Spraul, C W; Noll-Hussong, M

2014-08-01

315

Trajectories of Resilience, Depression, and Anxiety Following Spinal Cord Injury  

Microsoft Academic Search

Purpose\\/Objective: To investigate longitudinal trajectories of depression and anxiety symptoms following spinal cord injury (SCI) as well as the predictors of those trajectories. Research Method\\/Design: A longitudinal study of 233 participants assessed at 4 time points: within 6 weeks, 3 months, 1 year, and 2 years from the point of injury. Data were analyzed using latent growth mixture modeling to

George A. Bonanno; Paul Kennedy; Isaac R. Galatzer-Levy; Peter Lude; Mangus L. Elfström

2012-01-01

316

Food freezing with simultaneous surface dehydration: approximate prediction of weight loss during freezing and storage  

Microsoft Academic Search

Weight loss of unpackaged foods during freezing and later storage is an important quality and economic issue. It is originated on surface ice sublimation due to differences in water activity between food surface and the refrigerating air. Weight loss rate is determined by refrigerating conditions and product characteristics. The modelling of this phenomenon has merited very little attention; at present

Laura A. Campañone; Viviana O. Salvadori; Rodolfo H. Mascheroni

2005-01-01

317

Optical coherence tomography-based freeze-drying microscopy  

PubMed Central

A new type of freeze-drying microscope based upon time-domain optical coherence tomography is presented here (OCT-FDM). The microscope allows for real-time, in situ 3D imaging of pharmaceutical formulations in vials relevant for manufacturing processes with a lateral resolution of <7 ?m and an axial resolution of <5 ?m. Correlation of volumetric structural imaging with product temperature measured during the freeze-drying cycle allowed investigation of structural changes in the product and determination of the temperature at which the freeze-dried cake collapses. This critical temperature is the most important parameter in designing freeze-drying processes of pharmaceutical products. PMID:22254168

Mujat, Mircea; Greco, Kristyn; Galbally-Kinney, Kristin L.; Hammer, Daniel X.; Ferguson, R. Daniel; Iftimia, Nicusor; Mulhall, Phillip; Sharma, Puneet; Pikal, Michael J.; Kessler, William J.

2011-01-01

318

Postpartum Depression: An Interactional View.  

ERIC Educational Resources Information Center

Postpartum depression is conceptualized as a predictable developmental, family crisis, which occurs when the natural difficulties of childbirth are benignly mishandled. Tactics are illustrated for interdicting maladaptive interpersonal spirals, including normalizing conflicting complaints; reframing depression as positive but costly; regulating…

Kraus, Mary Ann; Redman, E. Scott

1986-01-01

319

Beating Depression …Help Is Available  

MedlinePLUS

... Bar Home Current Issue Past Issues Beating Depression …Help Is Available Past Issues / Summer 2007 Table of ... own battle with major depression. Photo: WireImage Getting Help "There's nothing, repeat, nothing to be ashamed of ...

320

Dementia: Depression and Alzheimer's Disease  

MedlinePLUS

MENU Return to Web version Dementia | Depression and Alzheimer’s Disease What is depression? When doctors talk about ... time Thoughts about death or suicide What is Alzheimer's disease? Alzheimer's disease is the most common type ...

321

Maternal Depression and Adolescent Behavior  

MedlinePLUS

... hand corner of the player. Maternal Depression and Adolescent Behavior HealthDay December 22, 2014 Related MedlinePlus Pages ... depression, how does it impact her child in adolescence? A new study published in the journal Pediatrics ...

322

Obstructive Sleep Apnea and Depression  

PubMed Central

Obstructive sleep apnea is a common sleep disorder associated with several medical conditions, increased risk of motor vehicle accidents, and overall healthcare expenditure. There is higher prevalence of depression in people with obstructive sleep apnea in both clinical and community samples. Many symptoms of depression and obstructive sleep apnea overlap causing under-diagnosis of obstructive sleep apnea in depressed patients. Sleep problems, including obstructive sleep apnea, are rarely assessed on a regular basis in patients with depressive disorders, but they may be responsible for antidepressant treatment failure. The mechanism of the relationship between obstructive sleep apnea and depression is complex and remains unclear. Though some studies suggest a mutual relationship, the relationship remains unclear. Several possible pathophysiological mechanisms could explain how obstructive sleep apnea can cause or worsen depression. Increased knowledge of the relationship between obstructive sleep apnea and depression might significantly improve diagnostic accuracy as well as treatment outcomes for both obstructive sleep apnea and depression. PMID:21922066

Ejaz, Shakir M.; Bhatia, Subhash; Hurwitz, Thomas D.

2011-01-01

323

Self-compassion in depression: associations with depressive symptoms, rumination, and avoidance in depressed outpatients.  

PubMed

Self-compassion involves being kind to oneself when challenged with personal weaknesses or hardship and has been claimed to be associated with resilience in various areas. So far, there are only a handful of studies that investigate self-compassion and its relation to clinical depression. Therefore, the principal goals of the present study were (a) to compare self-compassion in clinically depressed patients and never-depressed subjects, (b) to investigate self-compassion and its relation to cognitive-behavioral avoidance and rumination in depressed outpatients, and (c) to investigate rumination and avoidance as mediators of the relationship between self-compassion and depressive symptoms. One hundred and forty-two depressed outpatients and 120 never-depressed individuals from a community sample completed a self-report measure of self-compassion along with other measures. Results indicate that depressed patients showed lower levels of self-compassion than never-depressed individuals, even when controlled for depressive symptoms. In depressed outpatients, self-compassion was negatively related to depressive symptoms, symptom-focused rumination, as well as cognitive and behavioral avoidance. Additionally, symptom-focused rumination and cognitive and behavioral avoidance mediated the relationship between self-compassion and depressive symptoms. These findings extend previous research on self-compassion, its relation to depression, as well as processes mediating this relationship, and highlight the importance of self-compassion in clinically depressed patients. Since depressed patients seem to have difficulties adopting a self-compassionate attitude, psychotherapists are well advised to explore and address how depressed patients treat themselves. PMID:23768676

Krieger, Tobias; Altenstein, David; Baettig, Isabelle; Doerig, Nadja; Holtforth, Martin Grosse

2013-09-01

324

Freezing efficiency of Silver Iodide, ATD and Kaolinite in the contact freezing mode  

NASA Astrophysics Data System (ADS)

The importance of heterogeneous ice nucleation via contact freezing is one of the open questions in the atmospheric science community. In our laboratory, we built the Collision Nucleation CHamber (CLINCH) (Ladino et al. 2011) in which falling cloud droplets can collide with aerosol particles. In this study, contact freezing experiments are conducted to investigate the ice nucleation ability of silver iodide (AgI), kaolinite and Arizona Test Dust (ATD). Silver iodide has been known for its ice nucleation ability since 1940s (Vonnegut 1947) while kaolinite is a clay mineral and known to be a moderate ice nucleus. ATD is a commercial dust sample used by many groups to compare different setups. In CLINCH, size selected aerosol particles collide with water droplets of 80 µm diameter. With the extension in chamber length it is possible to vary the interaction time of ice nuclei and the droplets. Our experiments are performed between -10 to -36 ºC for various concentrations of ice nuclei and different interaction times. The frozen fraction of the droplets is determined using the custom-made depolarization detector IODE (Nicolet et al., 2010). Depolarization of linearly polarized incident laser light is used to determine the ratio of frozen droplets to all droplets. Frozen fractions of the three particle types with different residence times from CLINCH will be presented in this study. The number of collisions between a single droplet and several aerosol particles can be calculated by accounting for the theoretical collision efficiency at the experimental conditions in order to obtain the freezing efficiency (frozen fraction/number of collisions). Nucleation efficiency is compared with other contact freezing studies and with immersion freezing

Nagare, Baban; Marcolli, Claudia; Stetzer, Olaf; Lohmann, Ulrike

2014-05-01

325

Ultrastructure of the echinoderm cuticle after fast-freezing/freeze substitution and conventional chemical fixations.  

PubMed

The cuticles of the pedicellaria primordia in the sea urchin Paracentrotus lividus and of the tube foot disk in the sea star Asterias rubens were preserved by different methods, viz., glutaraldehyde fixation followed by osmium tetroxide postfixation, glutaraldehyde-ruthenium red fixation followed by osmium tetroxide-ruthenium red postfixation, and two fast freezing / freeze substitution methods (FF/FS). The gross ultrastructure of the cuticle as well as the influence of the preservation method on this ultrastructure were identical for the two tissues studied. The cuticle ultrastructure was poorly preserved after glutaraldehyde fixation / osmium tetroxide postfixation. Its preservation was improved after ruthenium red was added in the fixative and postfixative, but the best preservation was consistently achieved using FF/FS. Both low-pressure freezing (plunge freezing) and high-pressure freezing were tested, the latter giving seemingly better results. With these methods, the cuticle appeared to be composed of a proximal lower cuticle, an intermediate upper cuticle, and a distal fuzzy coat. In particular, cryoimmobilization methods emphasized or revealed the occurrence of a well-developed fibrillar lower cuticle in the pedicellaria, the complexity of the upper cuticle which consisted of several zones, and the importance of the usually poorly preserved fuzzy coat that is actually the thickest layer of the cuticle. These observations bring new insights on the functions of the cuticle, and particularly of the fuzzy coat. According to its preservation characteristics, the fuzzy coat presumably consists mostly of proteoglycans. This composition could give it shock absorption and antifouling properties. Furthermore, its important thickness also implies that molecules detected by the short sensory cilia must diffuse through and could be selected by the fuzzy coat. PMID:10738319

Ameye, L; Hermann, R; DuBois, P; Flammang, P

2000-03-15

326

Effect of repeated freeze-thaw cycles on geographically different populations of the freeze-tolerant worm Enchytraeus albidus (Oligochaeta).  

PubMed

Freeze-tolerant organisms survive internal ice formation; however, the adaptations to repeated freeze-thaw cycles are often not well investigated. Here we report how three geographically different populations of Enchytraeus albidus (Germany, Iceland and Svalbard) respond to three temperature treatments - constant thawed (0°C), constant freezing (-5°C) and fluctuating temperature (0 to -5°C) - over a period of 42 days. Survival varied between treatments and populations such that enchytraeids from arctic locations had a higher survival following prolonged freeze periods compared with temperate populations. However, enchytraeids from temperate locations had the same survival rate as arctic populations when exposed to repeated freeze-thaw events. Across all populations, metabolic rate decreased markedly in frozen animals (-5°C) compared with thawed controls (0°C). This decrease is likely due to the lower temperature of frozen animals, but also to the transition to the frozen state per se. Animals exposed to repeated freeze-thaw events had an intermediate metabolic rate and freeze-thaw events were not associated with pronounced excess energetic costs. Overwintering under either condition was not associated with a decrease in lipid content; however, during exposure to constant freezing and repeated freeze-thaw events there was a noticeable decrease in carbohydrate stores over time. Thus, animals exposed to constant freezing showed a decrease in glycogen stores, while both glucose and glycogen content decreased over time when the organisms were exposed to repeated freezing. The results therefore suggest that carbohydrate resources are important as a fuel for E. albidus during freezing whereas lipid resources are of marginal importance. PMID:25214492

Fisker, Karina Vincents; Holmstrup, Martin; Malte, Hans; Overgaard, Johannes

2014-11-01

327

RESPONSES TO FREEZING EXPOSURE OF HATCHLING TURTLES TRACHEMYS SCRIPTA ELEGANS: FACTORS INFLUENCING THE DEVELOPMENT OF FREEZE TOLERANCE BY REPTILES  

Microsoft Academic Search

Summary Hatchling red-eared turtles Trachemys (=Pseudemys) scripta elegans (Wied) from a Louisiana population display a significant ability to withstand the freezing of extracellular body fluids. All animals survived at least 2 h of freezing at -2.5 or —4°C. At -2.5°C, survival declined to 50% after 6h of freezing and no animals recovered after 24 h or longer, when mean ice

THOMAS A. CHURCHILL; KENNETH B. STOREY

328

Fundamental Boiling and RP-1 Freezing Experiments  

NASA Technical Reports Server (NTRS)

This paper describes results from experiments performed to help understand certain aspects of the MC-1 engine prestart thermal conditioning procedure. The procedure was constrained by the fact that the engine must chill long enough to get quality LOX at the LOX pump inlet but must be short enough to prevent freezing of RP-1 in the fuel pump. A chill test of an MC-1 LOX impeller was performed in LN2 to obtain data on film boiling, transition boiling and impeller temperature histories. The transition boiling data was important to the chill time so a subsequent experiment was performed chilling simple steel plates in LOX to obtain similar data for LOX. To address the fuel freezing concern, two experiments were performed. First, fuel was frozen in a tray and its physical characteristics were observed and temperatures of the fuel were measured. The result was physical characteristics as a function of temperature. Second was an attempt to measure the frozen thickness of RP-1 on a cold wall submerged in warm RP-1 and to develop a method for calculating that thickness for other conditions.

Goode, Brian; Turner, Larry D. (Technical Monitor)

2001-01-01

329

Continuous freezing condenser for phthalic anhydride. [Patented  

SciTech Connect

The increasing outputs of plastics and polymer materials necessitate correspondingly larger outputs of various organic monomers. Phthalic anhydride is one of the source products for organic synthesis. Phthalic anhydride is made in the coking industry by the catalytic vapor-phase oxidation of naphthalene. The product is difficult to isolate from the reaction mixture leaving the static-bed catalytic reactors, since the volume of gases and vapors to be cooled is very large and the phthalic anhydride concentration in the mixture is very low. Continuous freezing condensers have been developed, in which the gas stream is cooled by counterflow contact with a stream of solid granular material on which the phthalic anhydride is condensed. One serious drawback is the need to expend large amounts of heat to remelt the phthalic anhydride crystals. The low strength of the granulated solid substrate leads to dust formation in operation, and the dust contaminates the product. We have developed a condenser in which the freezing and remelting stages take place on metal balls in the same unit and the heat is derived from the incoming reaction mixture. Accordingly, units of large capacity can be constructed giving a higher product yield and lowering the heat consumption in the remelting stage.

Korobchanskii, V.I.; Grebenyuk, A.F.; Korobchanskii, Yu.V.; Il'in, A.P.

1981-01-01

330

Optimism, pessimism, and postpartum depression  

Microsoft Academic Search

This study examined the role of dispositional optimism versus pessimism as a moderator of the tendency to become depressed after a specific stressful life change: the birth of a child. The optimism-pessimism dimension was operationally defined as generalized expectancies for favorable versus unfavorable life outcomes. Both optimism and depressive mood were assessed several weeks before childbirth. Depressive mood was measured

Charles S. Carver; Joan Gollin Gaines

1987-01-01

331

Sadness, Depression, and Avoidance Behavior  

ERIC Educational Resources Information Center

Research into genetic, psychosocial, and cognitive explanations for depression (biopsychosocial models) provides support for the role of these variables in the etiology of depression. Regularly identified as basic to depression is loss, and the experience of loss has been found to be more influential than genetic factors in the causation of…

Leventhal, Allan M.

2008-01-01

332

The molecular neurobiology of depression  

Microsoft Academic Search

Unravelling the pathophysiology of depression is a unique challenge. Not only are depressive syndromes heterogeneous and their aetiologies diverse, but symptoms such as guilt and suicidality are impossible to reproduce in animal models. Nevertheless, other symptoms have been accurately modelled, and these, together with clinical data, are providing insight into the neurobiology of depression. Recent studies combining behavioural, molecular and

Vaishnav Krishnan; Eric J. Nestler

2008-01-01

333

Major Depression and Complicated Grief  

MedlinePLUS

... SEE A LIST » Grief, mourning, and bereavement Major depression and complicated grief Coping with loss Helping someone who is grieving Grief ... Previous Topic Grief, mourning, and bereavement Next Topic Coping with loss Major depression and complicated grief Depression It’s common for people ...

334

Discovering Endophenotypes for Major Depression  

Microsoft Academic Search

The limited success of genetic studies of major depression has raised questions concerning the definition of genetically relevant phenotypes. This paper presents strategies to improve the phenotypic definition of major depression by proposing endophenotypes at two levels: First, dissecting the depressive phenotype into key components results in narrow definitions of putative psychopathological endophenotypes: mood bias toward negative emotions, impaired reward

Gregor Hasler; Wayne C Drevets; Husseini K Manji; Dennis S Charney

2004-01-01

335

Maternal depression and parenting behavior  

Microsoft Academic Search

The results of 46 observational studies were analyzed to assess the strength of the association between depression and parenting behavior and to identify variables that moderated the effects. The association between depression and parenting was manifest most strongly for negative maternal behavior and was evident to a somewhat lesser degree in disengagement from the child. The association between depression and

M. Christine Lovejoy; Patricia A Graczyk; Elizabeth O'Hare; George Neuman

2000-01-01

336

Postpartum Depression and Child Development.  

ERIC Educational Resources Information Center

Only recently has the research on postpartum depression dealt with the disorder's effects on child development. This book explores the impact of postpartum depression on mother-infant interaction and child development, its treatment, and postpartum psychosis. The chapters are: (1) "The Nature of Postpartum Depressive Disorders" (Michael O'Hara);…

Murray, Lynne, Ed.; Cooper, Peter J., Ed.

337

Adult hippocampal neurogenesis in depression  

Microsoft Academic Search

The development of new treatments for depression is predicated upon identification of neural substrates and mechanisms that underlie its etiology and pathophysiology. The heterogeneity of depression indicates that its origin may lie in dysfunction of multiple brain regions. Here we evaluate adult hippocampal neurogenesis as a candidate mechanism for the etiology of depression and as a substrate for antidepressant action.

Amar Sahay; Rene Hen

2007-01-01

338

Freezing stress response in woody tissues observed using low-temperature scanning electron microscopy and freeze substitution techniques.  

PubMed

The objective of the current research was to examine the response of woody plant tissues to freezing stress by using scanning electron microscopy (SEM). Nonsupercooling species red osier dogwood (Cornus stolonifera Michx.), weeping willow (Salix babylonica L.), and corkscrew willow (Salix matsudana Koidz. f. tortuosa Rehd.) survived freezing stress as low as -60 degrees C. Cell collapse of ray parenchyma cells of these species was expected but did not occur. It was concluded that ray parenchyma cells of these species do not fit into either the supercooling or extracellular freezing classifications. Tissues from flowering dogwood (Cornus florida L.), apple (Malus domestica Borkh. cv "Starking III"), red oak (Quercus rubra L.), scarlet oak (Quercus coccinea Muench.), and red ash (Fraxinus pennsylvanica Marsh) were confirmed as supercooling species, and did not survive exposures below -40 degrees C. Ray parenchyma cells of these species did not collapse in response to freezing stress, as was expected. Cell collapse along the margins of voids were observed in bark of all seven species. Voids were the result of extracellular ice crystals formed in the bark during exposure to freezing stress. Tissues prepared by freeze substitution techniques were found to be adequately preserved when compared to those prepared by conventional fixation and low temperature SEM techniques. A freezing protocol for imposing freezing stress at temperatures lower than experienced naturally in the area where the study was conducted was developed that produced responses comparable to those observed in specimens collected in the field during natural freezing events. PMID:16668066

Malone, S R; Ashworth, E N

1991-03-01

339

Probability of freezing in the freeze-avoiding beetle larvae Cucujus clavipes puniceus (Coleoptera: Cucujidae) from interior Alaska.  

PubMed

Freeze-avoiding insects must resist freezing or die. A suite of adaptations to low temperatures, including the production of antifreeze proteins, colligative antifreezes (polyols), and dehydration allows most individuals to prevent freezing below the lowest ambient temperatures experienced in situ; however, there can be a wide variance in the minimum temperatures that individuals of freeze-avoiding species reach before freezing. We used logistic regression to explore factors that affect this variance and to estimate the probability of freezing in larvae of the freeze-avoiding beetle Cucujus clavipes puniceus. We hypothesized that water content ?0.5 mg mg(-1) dry mass would lead to deep supercooling (avoidance of freezing below -58°C). We found a significant interaction between water content and ambient below-snow temperature and a significant difference between individuals collected from two locations in Alaska: Wiseman and Fairbanks. Individuals collected in Wiseman deep supercooled with greater water content and to a greater range of ambient temperatures than individuals collected in Fairbanks, leading to significantly different lethal water contents associated with 50% probability of freezing. PMID:21550349

Sformo, T; McIntyre, J; Walters, K R; Barnes, B M; Duman, J

2011-08-01

340

Suicide and Depression  

MedlinePLUS

... to end the pain. This is when suicidal thinking begins. Depressive illnesses can distort thinking such that a person can’t think clearly ... focuses on trying to change a person's negative thinking and the inaccurate perceptions they have of themselves ...

341

Depression and Bone Metabolism  

Microsoft Academic Search

Background: There are data to suggest low bone mineral density is disproportionately prevalent among those with psychiatric disorders. This paper aims to review the current evidence on the relationship between depression and bone mineral density, and identify potential mechanisms. Methods: Relevant sources were identified from the Pubmed and Web of Science (ISI) databases from the first relevant publication in 1994

Lana J. Williams; Julie A. Pasco; Felice N. Jacka; Margaret J. Henry; Seetal Dodd; Michael Berk

2009-01-01

342

Cones with Summit Depressions  

USGS Multimedia Gallery

A cluster of cones with summit depressions in Coprates Chasma, Mars. These structures, morphologically speaking, resemble cinder cones. More likely, they are mud volcanoes. Mud volcanoes occur when a slurry of liquid, gas, and sediment is forced to the surface from a depth of several meters to sever...

343

Plain Talk about Depression. Plain Talk Series.  

ERIC Educational Resources Information Center

Depression is defined as a "whole-body" illness, involving the body, mood, and thoughts. Three of the most prevalent types of depressive disorders are described: major depression, dysthymia, and bipolar disorders (formerly called manic-depressive illness). Eleven symptoms of depression and 10 symptoms of mania are listed. Causes of depression are…

Sargent, Marilyn

344

Interplay between demixing and freezing in two-dimensional symmetrical mixtures.  

PubMed

The interplay between demixing and freezing in two-dimensional symmetrical binary mixtures of Lennard-Jones particles is studied using Monte Carlo simulation. It is demonstrated that different scenarios are possible. For example, the line of continuous liquid demixing transition can start at the liquid side of the vapor-liquid coexistence at the lower critical end point and then it can terminate at the liquid side of the liquid-demixed solid coexistence at the upper critical end point. Other situations are also possible. We distinguish four different scenarios depending on the interactions between unlike particles. PMID:20365417

Patrykiejew, A; Soko?owski, S

2010-01-01

345

Increased spring freezing vulnerability for alpine shrubs under early snowmelt.  

PubMed

Alpine dwarf shrub communities are phenologically linked with snowmelt timing, so early spring exposure may increase risk of freezing damage during early development, and consequently reduce seasonal growth. We examined whether environmental factors (duration of snow cover, elevation) influenced size and the vulnerability of shrubs to spring freezing along elevational gradients and snow microhabitats by modelling the past frequency of spring freezing events. We sampled biomass and measured the size of Salix herbacea, Vaccinium myrtillus, Vaccinium uliginosum and Loiseleuria procumbens in late spring. Leaves were exposed to freezing temperatures to determine the temperature at which 50% of specimens are killed for each species and sampling site. By linking site snowmelt and temperatures to long-term climate measurements, we extrapolated the frequency of spring freezing events at each elevation, snow microhabitat and per species over 37 years. Snowmelt timing was significantly driven by microhabitat effects, but was independent of elevation. Shrub growth was neither enhanced nor reduced by earlier snowmelt, but decreased with elevation. Freezing resistance was strongly species dependent, and did not differ along the elevation or snowmelt gradient. Microclimate extrapolation suggested that potentially lethal freezing events (in May and June) occurred for three of the four species examined. Freezing events never occurred on late snow beds, and increased in frequency with earlier snowmelt and higher elevation. Extrapolated freezing events showed a slight, non-significant increase over the 37-year record. We suggest that earlier snowmelt does not enhance growth in four dominant alpine shrubs, but increases the risk of lethal spring freezing exposure for less freezing-resistant species. PMID:24435708

Wheeler, J A; Hoch, G; Cortés, A J; Sedlacek, J; Wipf, S; Rixen, C

2014-05-01

346

P-wave velocity changes in freezing hard low-porosity rocks: a laboratory-based time-average model  

NASA Astrophysics Data System (ADS)

P-wave refraction seismics is a key method in permafrost research but its applicability to low-porosity rocks, that constitute alpine rock walls, has been denied in prior studies. These explain p-wave velocity changes in freezing rocks exclusively due to changing velocities of pore infill, i.e. water, air and ice. In existing models, no velocity increase is expected for low-porosity bedrock. We postulate, that mixing laws apply for high-porosity rocks, but freezing in confined space in low-porosity bedrock also alters physical rock matrix properties. In the laboratory, we measured p-wave velocities of 22 decimeter-large low-porosity (<6 %) metamorphic, magmatic and sedimentary permafrost rock samples with a natural texture (>100 micro-fissures) from 25 °C to -15 °C in 0.3 °C increments close to the freezing point. P-wave velocity increases by 7-78 % when freezing parallel to cleavage/bedding and matrix velocity increases from 5-59 % coincident to an anisotropy decrease in most samples. The expansion of rigid bedrock upon freezing is restricted and ice pressure will increase matrix velocity and decrease anisotropy while changing velocities of the pore infill are insignificant. Here, we present a modified Timur's 2-phase equation implementing changes in matrix velocity dependent on lithology and demonstrate the physical basis for refraction seismics in low-porosity bedrock.

Draebing, D.; Krautblatter, M.

2012-02-01

347

P-wave velocity changes in freezing hard low-porosity rocks: a laboratory-based time-average model  

NASA Astrophysics Data System (ADS)

P-wave refraction seismics is a key method in permafrost research but its applicability to low-porosity rocks, which constitute alpine rock walls, has been denied in prior studies. These studies explain p-wave velocity changes in freezing rocks exclusively due to changing velocities of pore infill, i.e. water, air and ice. In existing models, no significant velocity increase is expected for low-porosity bedrock. We postulate, that mixing laws apply for high-porosity rocks, but freezing in confined space in low-porosity bedrock also alters physical rock matrix properties. In the laboratory, we measured p-wave velocities of 22 decimetre-large low-porosity (< 10%) metamorphic, magmatic and sedimentary rock samples from permafrost sites with a natural texture (> 100 micro-fissures) from 25 °C to -15 °C in 0.3 °C increments close to the freezing point. When freezing, p-wave velocity increases by 11-166% perpendicular to cleavage/bedding and equivalent to a matrix velocity increase from 11-200% coincident to an anisotropy decrease in most samples. The expansion of rigid bedrock upon freezing is restricted and ice pressure will increase matrix velocity and decrease anisotropy while changing velocities of the pore infill are insignificant. Here, we present a modified Timur's two-phase-equation implementing changes in matrix velocity dependent on lithology and demonstrate the general applicability of refraction seismics to differentiate frozen and unfrozen low-porosity bedrock.

Draebing, D.; Krautblatter, M.

2012-10-01

348

Couple Discord and Depression in Couples during Couple Therapy and in Depressed Individuals during Depression Treatment  

ERIC Educational Resources Information Center

The association between depression and relationship distress as well as the impact of treatment for the one on the other was examined across 2 treatment-seeking samples: individuals seeking treatment for depression (N = 120) and couples seeking marital therapy (N = 134 couples). Although there was a baseline association between depression and…

Atkins, David C.; Dimidjian, Sona; Bedics, Jamie D.; Christensen, Andrew

2009-01-01

349

Large scale synthesis of nanostructured zirconia-based compounds from freeze-dried precursors  

SciTech Connect

Nanocrystalline zirconia powders have been obtained at the multigram scale by thermal decomposition of precursors resulting from the freeze-drying of aqueous acetic solutions. This technique has equally made possible to synthesize a variety of nanostructured yttria or scandia doped zirconia compositions. SEM images, as well as the analysis of the XRD patterns, show the nanoparticulated character of those solids obtained at low temperature, with typical particle size in the 10-15 nm range when prepared at 673 K. The presence of the monoclinic, the tetragonal or both phases depends on the temperature of the thermal treatment, the doping concentration and the nature of the dopant. In addition, Rietveld refinement of the XRD profiles of selected samples allows detecting the coexistence of the tetragonal and the cubic phases for high doping concentration and high thermal treatment temperatures. Raman experiments suggest the presence of both phases also at relatively low treatment temperatures. - Graphical abstract: Zr{sub 1-x}A{sub x}O{sub 2-x/2} (A=Y, Sc; 0{<=}x{<=}0.12) solid solutions have been prepared as nanostructured powders by thermal decomposition of precursors obtained by freeze-drying, and this synthetic procedure has been scaled up to the 100 g scale. Highlights: Black-Right-Pointing-Pointer Zr{sub 1-x}A{sub x}O{sub 2-x/2} (A=Y, Sc; 0{<=}x{<=}0.12) solid solutions have been prepared as nanostructured powders. Black-Right-Pointing-Pointer The synthetic method involves the thermal decomposition of precursors obtained by freeze-drying. Black-Right-Pointing-Pointer The temperature of the thermal treatment controls particle sizes. Black-Right-Pointing-Pointer The preparation procedure has been scaled up to the 100 g scale. Black-Right-Pointing-Pointer This method is appropriate for the large-scale industrial preparation of multimetallic systems.

Gomez, A.; Villanueva, R.; Vie, D.; Murcia-Mascaros, S.; Martinez, E.; Beltran, A. [Institut de Ciencia dels Materials, Parc Cientific, Universitat de Valencia, PO Box 22085, 46071 Valencia (Spain); Sapina, F., E-mail: fernando.sapina@uv.es [Institut de Ciencia dels Materials, Parc Cientific, Universitat de Valencia, PO Box 22085, 46071 Valencia (Spain); Vicent, M.; Sanchez, E. [Instituto de Tecnologia Ceramica-Asociacion de Investigacion de las Industrias Ceramicas, Universitat Jaume I, 12006 Castellon (Spain)

2013-01-15

350

SFT: a consistent checkpointing algorithm with shorter freezing time  

Microsoft Academic Search

SFT algorithm, a consistent checkpointing algorithm with shorter freezing time, is presented in this paper. SFT is able to implement fault-tolerance in distributed systems. The features of the algorithm include shorter freezing time, lower overhead, and simple roll backing. To reduce checkpointing time, a special control message (Munblock) is used to ensure that at any given time a process can

Xiaohui Wei; Jiubin Ju

1998-01-01

351

Glassy freezing in relaxor ferroelectric lead magnesium niobate  

Microsoft Academic Search

The freezing process in lead magnesium niobate (PMN) has been investigated by measurements of the frequency-dependent complex dielectric constant and its third harmonic component. The linear complex dielectric susceptibility was analyzed by a temperature-frequency plot in order to determine the temperature dependence of the dielectric relaxation spectrum and to identify the freezing temperature. It was found that both the shape

Adrijan Levstik; Zdravko Kutnjak; Cene Filipic; Rasa. Pirc

1998-01-01

352

Understanding freeze stress in biological tissues: thermodynamics of interfacial water  

Technology Transfer Automated Retrieval System (TEKTRAN)

A thermodynamic approach to distinguish forms of freeze energy that injure plants as the temperature decreases is developed. The pattern resulting from this analysis dictated the sequence of thermal requirements for water to exist as an independent state. Improvement of freezing tolerance in biolo...

353

Logistic Regression Analysis of Freezing Tolerance in Winter Wheat  

Technology Transfer Automated Retrieval System (TEKTRAN)

Four winter wheat cultivars, Eltan, Froid, Kestrel, and Tiber, were cold-acclimated for five weeks and then tested for freezing tolerance in a programmable freezer. The temperature of the soil was recorded every two minutes and the freezing episode was described as five parameters: the minimum temp...

354

ORIGINAL PAPER Effect of freezing-thawing on nitrogen mineralization  

E-print Network

ORIGINAL PAPER Effect of freezing-thawing on nitrogen mineralization in vegetation soils of four the effect of freezing-thawing on nitrogen (N) mineralization of four vegetation soils from typical . Soil nitrogen mineralization . Soil water content . Temperate forest . Changbai Mountain 1 Introduction

Boyer, Edmond

355

Freeze After Writing Quasi-Deterministic Parallel Programming with LVars  

E-print Network

Freeze After Writing Quasi-Deterministic Parallel Programming with LVars Lindsey Kuper Indiana: shared memory locations whose semantics are defined in terms of an application- specific lattice. Writes the ability to "freeze" and then read the contents of an LVar directly. Second, we add the ability to attach

Menczer, Filippo

356

FREEZE-FRACTURIN G IN ULTRAHIGH VACUUM AT -196  

Microsoft Academic Search

Conventional freeze-etching is carried out in a vacuum of -10 -~ torr and at a specimen temperature of -100~ The relatively poor topographic resolution of most freeze-etch replicas, and the lack of complementarity of morphological details in double replicas have been thought to be caused by structural distortions during fracturing, and radiation damage during replication. Both phenomena can be reduced

HEINZ GROSS; ENIS BAS; HANS MOOR

357

Research Review Falls and Freezing of Gait in Parkinson's Disease  

E-print Network

Society Key words: Parkinson's disease; falls; gait; freezing; patho- physiology; treatment In recentResearch Review Falls and Freezing of Gait in Parkinson's Disease: A Review of Two Interconnected that are common in Parkinson's disease. Both symp- toms are often incapacitating for affected patients

358

Effect of Freezing on Bacteriologic Culturing of Mastitis Milk Samples  

Microsoft Academic Search

The objective was to determine the effect of freezing and length of freezing in a commercial freezer on the qualitative results of bacteriologic culturing of milk collected from glands of cows with clini- cal or subclinical inwamammary infec- tions. A total of 182 milk samples from cows with clinical mastiffs and 55 milk samples of cows with subclinical mastiffs were

Y. H. Schukken; J. A. H. Smit; F. J. Grommers; D. Vandegeer; A. Brand

1989-01-01

359

Stopping biological time: The freezing of living cells  

SciTech Connect

The fundamental physical-chemical events that occur during the freezing and thawing of cells are outlined and the manner in which cell permeability determines the response of the cell to freezing is discussed both in terms of physical response and in terms of survival. 40 refs., 12 figs.

Mazur, P.

1987-01-01

360

Increasing Freezing Tolerance: Kinase Regulation of ICE1.  

PubMed

Cold temperatures trigger the ICE1-CBF-COR transcriptional cascade in plants, which reprograms gene expression to increase freezing tolerance. In this issue of Developmental Cell, Ding et al. (2015) report that cold stress activates the protein kinase OST1 to phosphorylate and thereby stabilize and stimulate ICE1. This enhances plant tolerance to freezing temperatures. PMID:25669879

Zhan, Xiangqiang; Zhu, Jian-Kang; Lang, Zhaobo

2015-02-01

361

7 CFR 305.18 - Quick freeze treatment schedule.  

Code of Federal Regulations, 2010 CFR

...false Quick freeze treatment schedule. 305.18...Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE...AGRICULTURE PHYTOSANITARY TREATMENTS Quick Freeze Treatments...during the 48-hour treatment period, but the temperature...States or its territorial waters, or is otherwise...

2010-01-01

362

Optimum Parameters for Freeze-Drying Decellularized Arterial Scaffolds  

PubMed Central

Decellularized arterial scaffolds have achieved success in advancing toward clinical use as vascular grafts. However, concerns remain regarding long-term preservation and sterilization of these scaffolds. Freeze drying offers a means of overcoming these concerns. In this study, we investigated the effects of various freeze-drying protocols on decellularized porcine carotid arteries and consequently, determined the optimum parameters to fabricate a stable, preserved scaffold with unaltered mechanical properties. Freeze drying by constant slow cooling to two final temperatures ((Tf), ?10°C and ?40°C) versus instant freezing was investigated by histological examination and mechanical testing. Slow cooling to Tf= ?10°C produced a stiffer and less distensible response than the non freeze-dried scaffolds and resulted in disruption to the collagen fibers. The mechanical response of Tf= ?40°C scaffolds demonstrated disruption to the elastin network, which was confirmed with histology. Snap freezing scaffolds in liquid nitrogen and freeze drying to Tf= ?40°C with a precooled shelf at ?60°C produced scaffolds with unaltered mechanical properties and a histology resembling non-freeze-dried scaffolds. The results of this study demonstrate the importance of optimizing the nucleation and ice crystal growth/size to ensure homogenous drying, preventing extracellular matrix disruption and subsequent inferior mechanical properties. This new manufacturing protocol creates the means for the preservation and sterilization of decellularized arterial scaffolds while simultaneously maintaining the mechanical properties of the tissue. PMID:23614758

Sheridan, William S.; Duffy, Garry P.

2013-01-01

363

Photomicrographic Investigation of Spontaneous Freezing Temperatures of Supercooled Water Droplets  

NASA Technical Reports Server (NTRS)

A photomicrographic technique for investigating eupercooled. water droplets has been devised and. used. to determine the spontaneous freezing temperatures of eupercooled. water droplets of the size ordinarily found. in the atmosphere. The freezing temperatures of 4527 droplets ranging from 8.75 to 1000 microns in diameter supported on a platinum surface and 571 droplets supported on copper were obtained. The average spontaneous freezing temperature decreased with decrease in the size of the droplets. The effect of size on the spontaneous freezing temperature was particularly marked below 60 microns. Frequency-distribution curves of the spontaneous freezing temperatures observed for droplets of a given size were obtained. Although no droplet froze at a temperature above 20 0 F, all droplets melted at 32 F. Results obtained with a copper support did not differ essentially from those obtained with a platinum surface.

Dorsch, R. G.; Hacker, P. T.

1950-01-01

364

Solar desalination by freezing and distillation  

NASA Astrophysics Data System (ADS)

It is noted that among seawater desalination processes the absorption-freeze vapor compression processes based on the thermal heat pump, although untested commercially and still in the development stage, appears technically and economically an attractive application of low-grade (exergy) solar heat. The distillation processes proposed here may be conveniently powered by low-grade solar heat (from flat plate solar collectors). It is expected that the scaling problem will be insignificant in comparison with that encountered in the conventional multistage flash process. The novel feature here is the use of enlarged capacity for heat exchange between distillate and brine via latent heat of solid-liquid phase change of a suitable hydrophobic intermediate heat transfer material.

Kvajic, G.

365

Free-energy functional for freezing transitions: Hard sphere systems freezing into crystalline and amorphous structures  

E-print Network

A free-energy functional that contains both the symmetry conserved and symmetry broken parts of the direct pair correlation function has been used to investigate the freezing of a system of hard spheres into crystalline and amorphous structures. The freezing parameters for fluid-crystal transition have been found to be in very good agreement with the results found from simulations. We considered amorphous structures found from the molecular dynamics simulations at packing fractions $\\eta$ lower than the glass close packing fraction $\\eta_{J}$ and investigated their stability compared to that of a homogeneous fluid. The existence of free-energy minimum corresponding to a density distribution of overlapping Gaussians centered around an amorphous lattice depicts the deeply supercooled state with a heterogeneous density profile.

Swarn Lata Singh; Atul S. Bharadwaj; Yashwant Singh

2011-01-31

366

Evaluation and Validation of the Messinger Freezing Fraction  

NASA Technical Reports Server (NTRS)

One of the most important non-dimensional parameters used in ice-accretion modeling and scaling studies is the freezing fraction defined by the heat-balance analysis of Messinger. For fifty years this parameter has been used to indicate how rapidly freezing takes place when super-cooled water strikes a solid body. The value ranges from 0 (no freezing) to 1 (water freezes immediately on impact), and the magnitude has been shown to play a major role in determining the physical appearance of the accreted ice. Because of its importance to ice shape, this parameter and the physics underlying the expressions used to calculate it have been questioned from time to time. Until now, there has been no strong evidence either validating or casting doubt on the current expressions. This paper presents experimental measurements of the leading-edge thickness of a number of ice shapes for a variety of test conditions with nominal freezing fractions from 0.3 to 1.0. From these thickness measurements, experimental freezing fractions were calculated and compared with values found from the Messinger analysis as applied by Ruff. Within the experimental uncertainty of measuring the leading-edge thickness, agreement of the experimental and analytical freezing fraction was very good. It is also shown that values of analytical freezing fraction were entirely consistent with observed ice shapes at and near rime conditions: At an analytical freezing fraction of unity, experimental ice shapes displayed the classic rime shape, while for conditions producing analytical freezing fractions slightly lower than unity, glaze features started to appear.

Anderson, David N.; Tsao, Jen-Ching

2005-01-01

367

Clarification on Mechanical Characteristic in State of Stress of Osteoarthritis of the Hip Joint Using Stress Freezing Method  

NASA Astrophysics Data System (ADS)

In this research, the Osteoarthritis of Hip Joint was pick up, the 3-dimensional stress freezing method of photoelastic method was applied, and the state of the stress in the normality hip joint and the transformable hip joint was examined. The direction and the singular point of principal stress and stress distribution were experimentally examined. At result, The Osteoarthritis of Hip Joint touches by 2 points, Osteoarthritis of Hip Joint occurrence of the new singular point with flat of the femoral head, They change the direction of the principal stress line in an existing singular point is cause.

Maezaki, Nobutaka; Ezumi, Tsutomu; Hachiya, Masashi

368

5-Hydroxytryptamine and depression  

PubMed Central

1 Theories linking 5-hydroxytryptamine (5-HT) with depression are briefly reviewed. The various experimental strategies adopted to investigate this relationship, examination of autopsy data, CSF metabolite data, 5-HT re-uptake patterns in human blood platelets and imipramine binding studies in human platelets, are discussed. 2 Recent studies of 5-hydroxyindole acetic acid (5-HIAA) levels in cerebrospinal fluid have revealed a linkage between low 5-HIAA levels and suicide, aggression and impulsivity. Decreases in the number of imipramine binding sites have also been found in brains of suicide victims. 3 The available data lead to the conclusion that decreased 5-hydroxytryptaminergic function may be associated with an increased risk of depression, suicide, and some types of aggression. ImagesFigure 2 PMID:6190490

Goodwin, F. K.; Post, R. M.

1983-01-01

369

Recognizing and Handling Depression for People with Diabetes  

MedlinePLUS

... out of it!” can’t cure depression. What causes depression? Researchers think depression is caused by a mix ... to depression? It isn’t clear whether diabetes causes depression or exactly how depression is related to diabetes. ...

370

Effect of wettability on sessile drop freezing: when superhydrophobicity stimulates an extreme freezing delay.  

PubMed

An increasing number of studies directed at supercooling water droplets on surfaces with different wettabilities have appeared in recent years. This activity has been stimulated by the recognition that water supercooling phenomena can be effectively used to develop methods for protecting outdoor equipment and infrastructure elements against icing and snow accretion. In this article, we discuss the nucleation kinetics of supercooled sessile water droplets on hydrophilic, hydrophobic, and superhydrophobic surfaces under isothermal conditions at temperatures of -8, -10, and -15 °C and a saturated water vapor atmosphere. The statistics of nucleation events for the ensembles of freezing sessile droplets is completed by the detailed analysis of the contact angle temperature dependence and freezing of individual droplets in a saturated vapor atmosphere. We have demonstrated that the most essential freezing delay is characteristic of the superhydrophobic coating on aluminum, with the texture resistant to contact with ice and water. This delay can reach many hours at T = -8 °C and a few minutes at -23 °C. The observed behavior is analyzed on the basis of different nucleation mechanisms. The dissimilarity in the total nucleation rate, detected for two superhydrophobic substrates having the same apparent contact angle of the water drop but different resistivities of surface texture to the contact with water/ice, is associated with the contribution of heterogeneous nucleation on external centers located at the water droplet/air interface. PMID:24491217

Boinovich, Ludmila; Emelyanenko, Alexandre M; Korolev, Vadim V; Pashinin, Andrei S

2014-02-18

371

Neurotrophins and depression  

Microsoft Academic Search

Exogenous delivery of the neurotrophic factors, brain-derived neurotrophic factor (BDNF) or neurotrophin-3 (NT-3), promotes the function, sprouting and regrowth of 5-HT-containing neurones in the brains of adult rats. Similar infusions of BDNF into the dorsal raphe nucleus produce an antidepressant effect, as evaluated by several ‘learned helplessness’ paradigms. Environmental stressors such as immobilization induce depression and decrease BDNF mRNA. Antidepressants

C. Anthony Altar

1999-01-01

372

Effects of freezing on the survival of Escherichia coli and Bacillus and response to UV and chlorine after freezing.  

PubMed

Escherichia coli (E. coli) and Bacillus megaterium bacteria were frozen at -15 degrees C using a freezer and a spray freezing method. The frozen Bacillus spores were also exposed to UV and free chlorine. An average of 4.7-log inactivation was obtained from the spray ice with 2-day storage time, while the freezer freezing only caused 0.84-log reduction with the same storage time. Significantly higher inactivation levels were observed for the E. coli cells with 2-day storage compared with those without storage. The spray freezing was found more effective in killing the E. coli cells, while more cells were sublethally injured by the freezer freezing. Freezing did not kill the Bacillus megaterium spores, but affected their response to UV and chlorine. Greater inactivation levels were observed at higher free chlorine doses or longer contact time, and the UV fluence-response curve showed initial rapid kill followed by tailing for the frozen spores. PMID:17571840

Gao, W; Smith, D W; Li, Y

2007-05-01

373

Pharmacotherapy of Postpartum Depression  

PubMed Central

Background The prevalence and recurrence rates of postpartum depression (PPD) are 13% and 25%, respectively. Despite its detrimental impact on the mother - infant dyad’s health, there is a paucity of data in the literature regarding the efficacy of pharmacological treatment of PPD. Objective 1)To review the literature on the use of antidepressants and hormonal supplements for the prevention and the treatment of PPD; 2) to provide the authors’ opinion regarding the current status of the pharmacological treatment of PPD, and 3) to discuss developments that are likely to be important in the future Methods An electronic search was performed by using PubMed, Medline, and PsychINFO. Inclusion criteria were: 1) empirical articles in peer-reviewed English language journals, 2) well validated measures of depression, and 3) uniform scoring system for depression among the sample. Results/Conclusion The electronic search yielded a total of 19 articles (12 on treatment and 7 on prevention of PPD) with the following study designs: 8 randomized clinical trials (6 usingplacebo control and 2 using active control groups), and 11 open label studies.The selection of the specific antidepressant for a woman with PPD should derive from a personalized risk-benefit analysis. PMID:19874247

Wisner, KL

2010-01-01

374

[Severe depression and work].  

PubMed

The prevalence of depression and processes liable to increase the severity of these disorders can be examined both by analysing the changes in the working environment and those relating to difficulties in diagnosis and treatment. The promotion of excellence, extensive competition in working relationships and the rise in different forms of violence, the increase in disadvantaged and unemployed populations are the major changes found : these result in an increase in work demands and by reduced resources to respond to these. The morbid process is liable to be increased due to the dual effect of the social invisibility of the disorder and people's isolation. Failure to manage patients and provide care may result in a worsening of the consequences of depression in terms of sustained incapacity or suicide attempts which are often seen in severe forms of depression. The treatment and prevention approach in this situation involves a combination of both care offered to the patient and interventions in the working environment in order to reduce their pathogenic potential. PMID:20141790

Lhuilier, D

2009-12-01

375

Studies on Freezing RAM Semen in Absence of Glycerol.  

NASA Astrophysics Data System (ADS)

Glycerol is widely used as a major cryoprotective agent for freezing spermatozoa of almost all species. However, it reduces fertility of sheep inseminated cervically compared with intrauterine insemination. Studies were conducted to develop a method and procedure for freezing ram semen in the absence of glycerol. Post -thaw survival of ram spermatozoa frozen in the absence of glycerol was affected by time and temperature after collection and before dilution and time after dilution and before freezing. Increase in time at 5^ circC before or after dilution and before freezing increased both post-thaw motility and number of cells passing through Sephadex filter. A cold dilution method was developed. Slow cooling of fresh ram semen and diluting at 5^circ C 2-3 hr. after collection, then freezing 1 hr. after dilution improved both post-thaw motility and number of cells passing through Sephadex filter compared with immediate dilution at 30-37^circC after collection and freezing 3-4 hr. later (P < 0.05). An extender was developed to freeze ram semen in the absence of glycerol. An increase in post-thaw motility was obtained when semen was extended in TES titrated with Tris to pH 7.0 (TEST) and osmotic pressure of 375-400 mOsm/kg, containing 25-30% (v/v) egg yolk and 10% (v/v) maltose. A special device (boat) for freezing was constructed to insure the same height of the sample above LN _2 and thus the same freezing rate from freeze to freeze. Freezing of semen in 0.25cc straws at 5-10 cm above LN_2 (73.8 to 49.5 ^circC/min) yielded higher post-thaw motility than the rates resulted from freezing at 15 cm above LN_2 or 1 cm above LN _2. Faster Thawing in 37^ circC water for 30 sec. (7.8^ circC/sec.) increased post-thaw motility compared with slower thawing in 5 or 20^circ C water (P < 0.05). A lambing rate of 52.2% was obtained in one fertility trial conducted with ram semen frozen without glycerol and 17.1% in a second trial. One injection (IM) of 15 mg PGF_{2alpha}/ewe for estrus synchronization during breeding season resulted in higher heat response and lambing rate than two injections given 10 days apart.

Abdelnaby, Abdelhady Abdelhakeam

1988-12-01

376

[Elderly depression and depressive state with Alzheimer's disease].  

PubMed

Depression and dementia, particularly Alzheimer's disease, are frequently observed in the elderly, and their diagnosis and treatment require complex knowledge of gerontology and psychiatry. Gerontologically, these diseases should be considered as geriatric syndrome. For the differentiation between depression and that associated with Alzheimer's disease, radiological examinations such as single photon emission CT and psychological examinations using the Geriatric Depression Scale (GDS) and Vitality Index are useful. Against depressive state with Alzheimer's disease, in addition to donepezil hydrochloride, selective serotonin reuptake inhibitors (SSRI) and serotonin-noradrenaline reuptake inhibitors (SNRI) are effective, and a small dose of sulpiride is also expected to be effective. In the treatment of elderly depression, its stage should be classified as acute or chronic. Treatment in the acute stage is similar to that in other age groups. In the chronic stage, activation treatment focusing on the prevention of functional decreases is necessary. For both depression and dementia, care and support for daily life are indispensable. PMID:19348250

Hattori, Hideyuki

2009-04-01

377

The Impact of Experiential Avoidance on the Reduction of Depression in Treatment for Borderline Personality Disorder  

PubMed Central

Background Reducing symptoms of depression is an important target in the treatment of borderline personality disorder (BPD). Although current treatments for BPD are effective in reducing depression, the average post-treatment level of depression remains high. Aim To test whether experiential avoidance (EA) impedes the reduction of depression during treatment for BPD. Method EA and depression were assessed in 81 clients at baseline and 4-month intervals during one year of therapy. Simple correlations, hierarchical linear modeling, and latent difference score models were used to investigate the association between self-reports of EA and both self-reports and observer-based ratings of depression. Results EA was positively associated with greater severity of depression at all points of assessment, and changes in EA were positively associated with changes in depression. Moreover, EA significantly predicted less subsequent reduction in depression whereas no such effect was found for depression on subsequent EA. Conclusion The findings are consistent with the hypothesis that EA impedes the reduction of depression in the treatment of BPD and should thus be considered an important treatment target. PMID:19477434

Berking, Matthias; Neacsiu, Andrada; Comtois, Katherine Anne; Linehan, Marsha Maria

2009-01-01

378

Relationship between freezing tolerance and shoot water relations of western red cedar.  

PubMed

Freezing tolerance and shoot water relations parameters of western red cedar (Thuja plicata Donn) seedlings were measured every 2 weeks from October 1989 to April 1990. Freezing tolerance, measured by freeze-induced electrolyte leakage, showed seasonal shifts in the temperature causing 50% foliage electrolyte leakage (LT(50)). The LT(50) value was -4 degrees C in October, it decreased to -20 degrees C in February and then increased to -6 degrees C in April. The foliage index of injury at -10 degrees C (II(-10)) also showed seasonal shifts from a high of 98% in October to a low of 18% in February followed by an increase to 82% in April. Osmotic potentials at saturation (Psi(s(sat))) and turgor loss point (Psi(s(tlp))) were, respectively, -1.07 and -1.26 MPa in October, -1.57 and -2.43 MPa in January, and -1.04 and -1.86 MPa in April. Dry weight fraction (DWF) increased and symplastic volume at full turgor (V(o)) decreased during the fall-winter acclimation phase, whereas DWF decreased and V(o) increased during the late winter-spring deacclimation phase. Relationships between seasonal patterns of freezing tolerance and shoot water relations parameters showed that LT(50) and II(-10) decreased linearly as Psi(s(tlp)) and V(o) decreased and DWF increased. There was no discernible difference in the relationship during fall acclimation or spring deacclimation. The freezing dehydration index at -10 degrees C (FDI(-10)) declined from 0.69 in November to 0.41 in February and increased to 0.56 in April. The value of II(-10) decreased linearly as FDI(-10) decreased, although a measurement made on actively growing spring foliage did not fit this relationship. The results indicate that seasonal changes in freezing tolerance of western red cedar are partially due to changes in tissue water content, symplastic volume, passive osmotic adjustment and FDI(-10). PMID:14969948

Grossnickle, S C

1992-10-01

379

Freeze-Thaw Durability of Air-Entrained Concrete  

PubMed Central

One of the most damaging actions affecting concrete is the abrupt temperature change (freeze-thaw cycles). The types of deterioration of concrete structures by cyclic freeze-thaw can be largely classified into surface scaling (characterized by the weight loss) and internal crack growth (characterized by the loss of dynamic modulus of elasticity). The present study explored the durability of concrete made with air-entraining agent subjected to 0, 100, 200, 300, and 400 cycles of freeze-thaw. The experimental study of C20, C25, C30, C40, and C50 air-entrained concrete specimens was completed according to “the test method of long-term and durability on ordinary concrete” GB/T 50082-2009. The dynamic modulus of elasticity and weight loss of specimens were measured after different cycles of freeze-thaw. The influence of freeze-thaw cycles on the relative dynamic modulus of elasticity and weight loss was analyzed. The findings showed that the dynamic modulus of elasticity and weight decreased as the freeze-thaw cycles were repeated. They revealed that the C30, C40, and C50 air-entrained concrete was still durable after 300 cycles of freeze-thaw according to the experimental results. PMID:23576906

Shang, Huai-Shuai; Yi, Ting-Hua

2013-01-01

380

Metabolic changes in Avena sativa crowns recovering from freezing.  

PubMed

Extensive research has been conducted on cold acclimation and freezing tolerance of fall-sown cereal plants due to their economic importance; however, little has been reported on the biochemical changes occurring over time after the freezing conditions are replaced by conditions favorable for recovery and growth such as would occur during spring. In this study, GC-MS was used to detect metabolic changes in the overwintering crown tissue of oat (Avena sativa L.) during a fourteen day time-course after freezing. Metabolomic analysis revealed increases in most amino acids, particularly proline, 5-oxoproline and arginine, which increased greatly in crowns that were frozen compared to controls and correlated very significantly with days after freezing. In contrast, sugar and sugar related metabolites were little changed by freezing, except sucrose and fructose which decreased dramatically. In frozen tissue all TCA cycle metabolites, especially citrate and malate, decreased in relation to unfrozen tissue. Alterations in some amino acid pools after freezing were similar to those observed in cold acclimation whereas most changes in sugar pools after freezing were not. These similarities and differences suggest that there are common as well as unique genetic mechanisms between these two environmental conditions that are crucial to the winter survival of plants. PMID:24675792

Henson, Cynthia A; Duke, Stanley H; Livingston, David P

2014-01-01

381

Dynamical freeze-out in three-fluid hydrodynamics  

SciTech Connect

The freeze-out procedure accepted in a model of three-fluid dynamics is analyzed. This procedure is formulated in terms of drain terms in hydrodynamic equations. The dynamics of freeze-out is illustrated by one-dimensional simulations. It is demonstrated that the resulting freeze-out reveals a nontrivial dynamics depending on initial conditions in the expanding 'fireball'. The freeze-out front is not just defined 'geometrically' on the condition of the freeze-out criterion met but rather is a subject of fluid evolution. It competes with the fluid flow and does not always reach the place where the freeze-out criterion is met. Dynamics of the freeze-out in three-dimensional simulations is analyzed. It is demonstrated that the late stage of central nuclear collisions at the top energies available at the CERN Super Proton Synchrotron is of the form of three (two baryon-rich and one baryon-free) fireballs separated from each other.

Russkikh, V. N.; Ivanov, Yu. B. [Gesellschaft fuer Schwerionenforschung mbH, Planckstr. 1, D-64291 Darmstadt (Germany); Kurchatov Institute, Kurchatov sq. 1, RU-123182 Moscow (Russian Federation)

2007-11-15

382

Metabolic Changes in Avena sativa Crowns Recovering from Freezing  

PubMed Central

Extensive research has been conducted on cold acclimation and freezing tolerance of fall-sown cereal plants due to their economic importance; however, little has been reported on the biochemical changes occurring over time after the freezing conditions are replaced by conditions favorable for recovery and growth such as would occur during spring. In this study, GC-MS was used to detect metabolic changes in the overwintering crown tissue of oat (Avena sativa L.) during a fourteen day time-course after freezing. Metabolomic analysis revealed increases in most amino acids, particularly proline, 5-oxoproline and arginine, which increased greatly in crowns that were frozen compared to controls and correlated very significantly with days after freezing. In contrast, sugar and sugar related metabolites were little changed by freezing, except sucrose and fructose which decreased dramatically. In frozen tissue all TCA cycle metabolites, especially citrate and malate, decreased in relation to unfrozen tissue. Alterations in some amino acid pools after freezing were similar to those observed in cold acclimation whereas most changes in sugar pools after freezing were not. These similarities and differences suggest that there are common as well as unique genetic mechanisms between these two environmental conditions that are crucial to the winter survival of plants. PMID:24675792

Henson, Cynthia A.; Duke, Stanley H.; Livingston, David P.

2014-01-01

383

Freeze-thaw durability of air-entrained concrete.  

PubMed

One of the most damaging actions affecting concrete is the abrupt temperature change (freeze-thaw cycles). The types of deterioration of concrete structures by cyclic freeze-thaw can be largely classified into surface scaling (characterized by the weight loss) and internal crack growth (characterized by the loss of dynamic modulus of elasticity). The present study explored the durability of concrete made with air-entraining agent subjected to 0, 100, 200, 300, and 400 cycles of freeze-thaw. The experimental study of C20, C25, C30, C40, and C50 air-entrained concrete specimens was completed according to "the test method of long-term and durability on ordinary concrete" GB/T 50082-2009. The dynamic modulus of elasticity and weight loss of specimens were measured after different cycles of freeze-thaw. The influence of freeze-thaw cycles on the relative dynamic modulus of elasticity and weight loss was analyzed. The findings showed that the dynamic modulus of elasticity and weight decreased as the freeze-thaw cycles were repeated. They revealed that the C30, C40, and C50 air-entrained concrete was still durable after 300 cycles of freeze-thaw according to the experimental results. PMID:23576906

Shang, Huai-Shuai; Yi, Ting-Hua

2013-01-01

384

Systematics of Kinetic Freeze-out Properties in High Energy Collisions from STAR  

E-print Network

The main aim of the RHIC Beam Energy Scan (BES) program is to explore the QCD phase diagram which includes search for a possible QCD critical point and the phase boundary between QGP and hadronic phase. We report the collision energy and centrality dependence of kinetic freeze-out properties from the measured mid-rapidity ($|y|<0.1)$ light hadrons (pions, kaons, protons and their anti-particles) for Au+Au collisions at the center-of-mass energy $\\sqrt{s_{NN}} =$ 7.7, 11.5, 19.6, 27, and 39 GeV. The STAR detector, with a large uniform acceptance and excellent particle identification is used in the data collection and analysis. The kinetic freeze-out temperature $T_{\\rm{kin}}$ and average collective velocity $\\langle \\beta \\rangle$ parameters are extracted from blast-wave fits to the identified hadron spectra and systematically compared with the results from other collision energies including those at AGS, SPS and LHC. It is found that all results fall into an anti-correlation band in the 2-dimension ($T_{\\rm{kin}}$, $\\langle \\beta \\rangle$) distribution: the largest value of collective velocity and lowest temperature is reached in the most central collisions at the highest collision energy. The energy dependence of these freeze-out parameters are discussed.

Lokesh Kumar

2014-08-19

385

Systematics of kinetic freeze-out properties in high energy collisions from STAR  

NASA Astrophysics Data System (ADS)

The main aim of the RHIC Beam Energy Scan (BES) program is to explore the QCD phase diagram which includes search for a possible QCD critical point and the phase boundary between QGP and hadronic phase. We report the collision energy and centrality dependence of kinetic freeze-out properties from the measured mid-rapidity (| y | < 0.1) light hadrons (pions, kaons, protons and their anti-particles) for Au + Au collisions at the center-of-mass energy ?{sNN} = 7.7 , 11.5 , 19.6 , 27 , and 39 GeV. The STAR detector, with a large uniform acceptance and excellent particle identification is used in the data collection and analysis. The kinetic freeze-out temperature Tkin and average collective velocity < ? > parameters are extracted from blast-wave fits to the identified hadron spectra and systematically compared with the results from other collision energies including those at AGS, SPS and LHC. It is found that all results fall into an anti-correlation band in the 2-dimensional (Tkin, < ? >) distribution: the largest value of collective velocity and lowest temperature is reached in the most central collisions at the highest collision energy. The energy dependence of these freeze-out parameters is discussed.

Kumar, Lokesh

2014-11-01

386

Air-Cooled Stack Freeze Tolerance Freeze Failure Modes and Freeze Tolerance Strategies for GenDriveTM Material Handling Application Systems and Stacks Final Scientific Report  

SciTech Connect

Air-cooled stack technology offers the potential for a simpler system architecture (versus liquid-cooled) for applications below 4 kilowatts. The combined cooling and cathode air allows for a reduction in part count and hence a lower cost solution. However, efficient heat rejection challenges escalate as power and ambient temperature increase. For applications in ambient temperatures below freezing, the air-cooled approach has additional challenges associated with not overcooling the fuel cell stack. The focus of this project was freeze tolerance while maintaining all other stack and system requirements. Through this project, Plug Power advanced the state of the art in technology for air-cooled PEM fuel cell stacks and related GenDrive material handling application fuel cell systems. This was accomplished through a collaborative work plan to improve freeze tolerance and mitigate freeze-thaw effect failure modes within innovative material handling equipment fuel cell systems designed for use in freezer forklift applications. Freeze tolerance remains an area where additional research and understanding can help fuel cells to become commercially viable. This project evaluated both stack level and system level solutions to improve fuel cell stack freeze tolerance. At this time, the most cost effective solutions are at the system level. The freeze mitigation strategies developed over the course of this project could be used to drive fuel cell commercialization. The fuel cell system studied in this project was Plug Power's commercially available GenDrive platform providing battery replacement for equipment in the material handling industry. The fuel cell stacks were Ballard's commercially available FCvelocity 9SSL (9SSL) liquid-cooled PEM fuel cell stack and FCvelocity 1020ACS (Mk1020) air-cooled PEM fuel cell stack.

Hancock, David, W.

2012-02-14

387

Immersion freezing on mineral dust particles  

NASA Astrophysics Data System (ADS)

Mineral dust is considered to play a major role in ice cloud nucleation in the troposphere. More than 1.000 Tg of mineral dust are aerosolized from the ground every year, 1-10% of these reach the upper troposphere [1]. At an altitude of about 8 km ice residual particle analysis has shown that about 50% of all ice nuclei (IN) are mineral dust[2]. In principle, natural occurring dusts may either be IN-active themselves or are carriers of organic and/or biological IN. Up to now the ice nucleation, i.e. cloud glaciation, has not been quantized. However, different authors report a high IN-activity for many mineral dust samples, although a systematic comparison between different minerals is still missing. Therefore, we studied selected mineral dust samples which were characterized by X-ray diffraction, FTIR spectroscopy, and scanning electron microscopy before use. Oil immersion measurements were performed on the most common minerals, clay materials and volcanic ash. The median freezing temperatures range from -21°C up to homogenous freezing at 38°C. Even though quite a few dust samples show a reasonable high IN-activity, their median freezing temperatures are low compared to biological samples [3, 4]. Furthermore, heat treatment of the dusts was applied in order to decompose and to denaturize organic and/or biological surfactants. Finally, some dust samples had a high loss of activity and thus were subjects of further experiments. These mineral dust particles were suspended in water and after an incubation time were removed. In some cases the washing water had become IN-active, but lost its activity after enzymatic treatment. The observed high IN-activity can thus be explained by adsorbed biological materials. The results suggest that some mineral dusts are IN-active, and if it is not intrinsic they may even enhance IN-activity of organic and biological IN if these are adsorbed on the dust particle surface. A relatively high IN-activity of the pure mineral dusts was only observed in quartz, clays, and mixed natural dusts (ATD), which are mainly composed of SiO2 and clays. References. [1] C. S. Zender, R. L. Miller and I. Tegen, Eos Trans. AGU, 2004,85, 509. [2] K. A. Pratt, P. J. DeMott, J. R. French, Z. Wang, D. L. Westphal, A. J. Heymsfield, C. H. Twohy, A. J. Prenni, K. A. Prather, Nat. Geosci., 2009, 2, 397-400. [3] B. Pummer, H. Bauer, J. Bernardi, S. Bleicher and H. Grothe, Atmos. Chem. Phys., 2012, 12, 2541-2550. [4] V. T. J. Phillips, C. Andronache, B. Christner, C. E. Morris, D. C. Sands, A. Bansemer, A. Lauer, C. McNaughton and C. Seman, Biogeosciences, 2009, 6, 987-1014.

Zolles, Tobias; Grothe, Hinrich; Pummer, Bernhard

2013-04-01

388

Subthreshold Symptoms of Depression in Preadolescent Girls Are Stable and Predictive of Depressive Disorders  

ERIC Educational Resources Information Center

Symptoms of depression are investigated among 232 preadolescent girls to study if they were predictive and stable of depression. Findings show that early symptoms of depression among preadolescent girls predict depressive disorders. Implications for preventive measures are discussed.

Keenan, Kate; Hipwell, Alsion; Feng, Xin; Babinski, Dara; Hinze, Amanda; Rischall, Michal; Henneberger, Angela

2008-01-01

389

Maladaptive Perfectionism and Ineffective Coping as Mediators Between Attachment and Future Depression: A Prospective Analysis  

Microsoft Academic Search

This study used a longitudinal design to examine whether maladaptive perfectionism and ineffective coping served as 2 mediators of the relation between adult attachment and future depression. Data were collected from 372 undergraduates at 2 time points. Results indicated that (a) the impact of attachment on future depression was mediated through future maladaptive perfectionism and ineffective coping, (b) ineffective coping

Meifen Wei; P. Paul Heppner; Daniel W. Russell; Shannon K. Young

2006-01-01

390

An Evaluation of Depressed Mood in Two Classes of Medical Students  

ERIC Educational Resources Information Center

Objective: To assess depression rates in contemporary medical students. Method: The Beck Depression Inventory (BDI) was administered anonymously to two medical school classes at matriculation, the end of first year, and the end of second year. Results: Median scores for both classes were low at all points. The proportion of students scoring in the…

Levine, Ruth E.; Litwins, Stephanie D.; Frye, Ann W.

2006-01-01

391

Review of brain functioning in depression for semantic processing and verbal fluency  

Microsoft Academic Search

Neurobiological models of depression point to brain regions that are proposed to be involved with both emotion regulation and language processing. This qualitative review focused on neurophysiological evidence for semantic processing and verbal fluency deficits associated with left frontal lobe and dorsolateral prefrontal cortex functioning in depression, respectively. Findings suggest that there are no behavioral or neurophysiological evidence of performance

Heide Klumpp; Patricia Deldin

2010-01-01

392

Early Adolescent Depressive Mood: Direct and Indirect Effects of Attributional Styles and Coping  

ERIC Educational Resources Information Center

The present study used a cross-sectional survey design to examine how adolescent depressive mood was related to attributional styles and coping strategies with a sample of 326 youths (aged 8-14 years). With the cutting point adopted in the West, 20.9% of the current sample reported depressive symptoms. Regression analysis results show that, with…

Chan, Siu Mui

2012-01-01

393

Maladaptive Perfectionism and Ineffective Coping as Mediators between Attachment and Future Depression: A Prospective Analysis  

ERIC Educational Resources Information Center

This study used a longitudinal design to examine whether maladaptive perfectionism and ineffective coping served as 2 mediators of the relation between adult attachment and future depression. Data were collected from 372 undergraduates at 2 time points. Results indicated that (a) the impact of attachment on future depression was mediated through…

Wei, Meifen; Heppner, P. Paul; Russell, Daniel W.; Young, Shannon K.

2006-01-01

394

School-Based Prevention of Depression: A Randomised Controlled Study of the "beyondblue" Schools Research Initiative  

ERIC Educational Resources Information Center

Background: Depressive disorders are experienced by 3-5% of the adolescent population at any point of time. They adversely affect adolescent development in a range of areas and greatly increase risk for suicide. The present study investigated the effectiveness of a universal intervention designed to reduce depressive symptoms among students…

Sawyer, Michael G.; Pfeiffer, Sara; Spence, Susan H.; Bond, Lyndal; Graetz, Brian; Kay, Debra; Patton, George; Sheffield, Jeanie

2010-01-01

395

Freeze-out volume of hot dense fireball  

E-print Network

A thermodynamically consistent excluded volume model is proposed to account for the particle multiplicities obtained from lowest SIS energies to the highest RHIC energies. The chemical freeze-out volumes lying in a slice of one unit of rapidity for pions and kaons are separately inferred from this analysis and the results are compared with the corresponding thermal freeze-out volumes obtained from the Hanbury-Brown Twiss (HBT) pion interferometry. Furthermore, we extract the variations of freeze-out number densities for pions and nucleons with the center-of-mass energy in our model and compare them with the HBT data.

M. Mishra; C. P. Singh

2007-09-27

396

PEM Fuel Cell Freeze Durability and Cold Start Project  

SciTech Connect

UTC has taken advantage of the unique water management opportunities inherent in micro-porous bipolar-plates to improve the cold-start performance of its polymer electrolyte fuel cells (PEFC). Diagnostic experiments were used to determine the limiting factors in micro-porous plate PEFC freeze performance and the causes of any performance decay. Alternative cell materials were evaluated for their freeze performance. Freeze-thaw cycling was also performed to determine micro-porous plate PEFC survivability. Data from these experiments has formed the basis for continuing development of advanced materials capable of supporting DOE's cold-start and durability objectives.

Patterson, T.; O'Neill, Jonathan

2008-01-02

397

322 sperm preservation by freeze-drying in endangered animals.  

PubMed

Sperm preservation is a useful tool for conservation of endangered animals. Freeze-drying sperm have been studied as new preservation method in various mammals as samples can be preserved in a refrigerator at 4°C or ambient temperature. Sperm preservation by freeze-drying is the ultimate method by which sperm can be stored that neither required specialised cryoprotectants nor constant supply of liquid nitrogen. We established the freeze-drying method that mouse and rat sperm could be preserved long-term at 4°C after freeze-drying using a simple solution containing 10mM Tris and 1mM EDTA (TE buffer; 2012 PLoS ONE 7, e35043; 2012 Cryobiology 64, 211-214). Using this method, the fertility of the chimpanzee, giraffe, and jaguar sperm after freeze-drying were estimated. Ejaculated chimpanzee and giraffe and cauda epididymal jaguar sperm were freeze-dried using TE buffer. Sperm were rehydrated with sterile distilled water after storage at 4°C for 1 month. Sperm with normal shape were injected into mouse oocytes in CZB medium with HEPES, and oocytes were then cultured in vitro for 6 to 8h in the same media. In all animals, pronuclei and sperm tail were observed into oocytes without artificial activation after injection of freeze-dried sperm. When chimpanzee, giraffe, and jaguar sperm were injected into oocytes, 86% (12/14), 100% (12/12), and 96% (22/23) of oocytes formed 2 distinct pronuclei. This study demonstrated that the sperm of various animals could be decondensed into the mouse oocytes after freeze-drying using the same protocol. A further advantage is that freeze-dried sperm can be transported oversea at ambient temperature. Freeze-drying preservation without using liquid nitrogen can be protected strongly valuable gametes of endangered animals even in the event of unexpected accidents and disaster such as earthquakes and typhoons. Freeze-drying of sperm has been applied as a "freeze-drying zoo" for conservation of endangered animals (http://www.anim.med.kyoto-u.ac.jp/reproduction/home.aspx). PMID:25472370

Kaneko, T

2014-12-01

398

[Association of obesity and depression].  

PubMed

It has been long known that the frequency of overweight and obese people is higher among depressed and bipolar patients than in the general population. The marked alteration of body weight (and appetite) is one of the most frequent of the 9 symptoms of major depressive episode, and these symptoms occur during recurrent episodes of depression with a remarkably high consequence. According to studies with representative adult population samples, in case of obesity (BMI over 30) unipolar or bipolar depression is significantly more frequently (20-45%) observable. Since in case of depressed patients appetite and body weight reduction is observable during the acute phase, the more frequent obesity in case of depressed patients is related (primarily) not only to depressive episodes, but rather to lifestyle factors, to diabetes mellitus also more frequently occurring in depressed patients, to comorbid bulimia, and probably to genetic-biological factors (as well as to pharmacotherapy in case of medicated patients). At the same time, according to certain studies, circadian symptoms of depression give rise to such metabolic processes in the body which eventually lead to obesity and insulin resistance. According to studies in unipolar and bipolar patients, 57-68% of patients is overweight or obese, and the rate of metabolic syndrome was found to be between 25-49% in bipolar patients. The rate of metabolic syndrome is further increased by pharmacotherapy. Low total and HDL cholesterol level increases the risk for depression and suicide and recent studies suggest that omega-3-fatty acids possess antidepressive efficacy. Certain lifestyle factors relevant to healthy metabolism (calorie reduction in food intake, regular exercise) may be protective factors related to depression as well. The depression- and possibly suicide-provoking effect of sibutramine and rimonabant used in the pharmacotherapy of obesity is one of the greatest recent challenges for professionals and patients alike. PMID:19213197

Rihmer, Zoltán; Purebl, György; Faludi, Gábor; Halmy, László

2008-10-01

399

Is Enceladus' Internal Ocean Doomed to Freeze?  

NASA Astrophysics Data System (ADS)

Enceladus is geologically hyperactive, with plumes of water vapor, other volatiles such as ammonia, and salty particles erupting from its South Polar Terrain. The plumes are spatially associated with a region of greatly increased local heat flux, with a total power output 15.8 × 3.1 GW spread over an area of 70,000 km2 (e.g., Spencer and Nimmo 2013, AREPS 41), corresponding to a regional heat flux of 180-270 mW m-2. Tidal strains of the magnitude only possible in an ice shell that is decoupled from a rocky interior by an internal ocean or regional sea are required to generate this much heat (e.g., Behounkova et al. 2012, Icarus 219). Yet, numerous studies conclude that Enceladus' ocean cannot be in present-day thermodynamic steady state with a conductive or convective ice I shell (e.g., Roberts and Nimmo 2008, Icarus 194; Behounkova et al. 2012). Regardless of where Enceladus' tidal heating is concentrated (i.e., the poles), and regardless of whether its outer ice I shell convects, Enceladus' ocean is predicted to freeze on a geologically rapid time scale, implying that activity on Enceladus is only a transient or episodic phenomenon. These arguments strictly apply only to pure water ice oceans, however. We have previously argued that if the presence of salts or ammonia is allowed for, the ocean may be cooler and can be maintained essentially permanently by tidal heating in the ice above (McKinnon and Barr 2008, LPS XXXIX). Here we elaborate on the conditions under which Enceladus' ocean can be stabilized or even increase in thickness due to present-day tidal heating within the ice shell and the presence of salts and ammonia, which we now know are there (Waite et al. 2009, Nature 460; Postberg et al. 2011, Nature 474). As previous work has found, we cannot explain the present-day heat flow, but there is no fundamental reason that Enceladus' ocean or sea should completely freeze for present-day orbital eccentricities.

McKinnon, W. B.; Barr, A. C.

2013-12-01

400

Depressive symptoms associated with sexual assault  

Microsoft Academic Search

The Beck Depression Inventory was used to assess depressive symptoms in 178 sexual assault survivors and 50 control subjects who had never been sexually assaulted. The sexual assault survivors reported significantly more depressive symptoms than the control subjects, and further analyses strongly suggested that the depressive symptoms were caused by the sexual assault. Investigation of the relationships between depression scores

Judith V. Becker; Linda J. Skinner; Gene G. Abel; Roz Axelrod; Eileen C. Treacy

1984-01-01

401

Adolescent depression: Description, causes, and interventions  

Microsoft Academic Search

Depression is one of the most prevalent of the psychiatric disorders and is common among individuals with epilepsy. Depression often begins in adolescence. The present review focuses on adolescent depression. In particular, this review first summarizes the definition, description, and classification of adolescent depression. Next, potential causes of adolescent depression are reviewed from a vulnerability–stress perspective. This part of the

Benjamin L. Hankin

2006-01-01

402

October is... National Depression Awareness Month  

E-print Network

common causes Depressive illnesses can be caused or influenced by a number of factors including: life professional to talk about causes of depression and coping techniques. · Call for an over the phone depressionOctober is... National Depression Awareness Month October is... National Depression Awareness Month

Burke, Peter

403

Modeling depression in Parkinson disease  

PubMed Central

Objective: To construct a model for depression in Parkinson disease (PD) and to study the relative contribution of PD-specific and nonspecific risk factors to this model. Methods: Structural equation modeling of direct and indirect associations of risk factors with the latent depression outcome using a cross-sectional dataset of 342 patients with PD. Results: A model with acceptable fit was generated that explained 41% of the variance in depression. In the final model, 3 PD-specific variables (increased disease duration, more severe motor symptoms, the use of levodopa) and 6 nonspecific variables (female sex, history of anxiety and/or depression, family history of depression, worse functioning on activities of daily living, and worse cognitive status) were maintained and significantly associated with depression. Nonspecific risk factors had a 3-times-higher influence in the model than PD-specific risk factors. Conclusion: In this cross-sectional study, we showed that nonspecific factors may be more prominent markers of depression than PD-specific factors. Accordingly, research on depression in PD should focus not only on factors associated with or specific for PD, but should also examine a wider scope of factors including general risk factors for depression, not specific for PD. PMID:23946309

Moonen, Anja J.H.; Dujardin, Kathy; Marsh, Laura; Martinez-Martin, Pablo; Richard, Irene H.; Starkstein, Sergio E.; Köhler, Sebastian

2013-01-01

404

Inner ear tissue preservation by rapid freezing: improving fixation by high-pressure freezing and hybrid methods.  

PubMed

In the preservation of tissues in as 'close to life' state as possible, rapid freeze fixation has many benefits over conventional chemical fixation. One technique by which rapid freeze-fixation can be achieved, high pressure freezing (HPF), has been shown to enable ice crystal artefact-free freezing and tissue preservation to greater depths (more than 40 ?m) than other quick-freezing methods. Despite increasingly becoming routine in electron microscopy, the use of HPF for the fixation of inner ear tissue has been limited. Assessment of the quality of preservation showed routine HPF techniques were suitable for preparation of inner ear tissues in a variety of species. Good preservation throughout the depth of sensory epithelia was achievable. Comparison to chemically fixed tissue indicated that fresh frozen preparations exhibited overall superior structural preservation of cells. However, HPF fixation caused characteristic artefacts in stereocilia that suggested poor quality freezing of the actin bundles. The hybrid technique of pre-fixation and high pressure freezing was shown to produce cellular preservation throughout the tissue, similar to that seen in HPF alone. Pre-fixation HPF produced consistent high quality preservation of stereociliary actin bundles. Optimising the preparation of samples with minimal artefact formation allows analysis of the links between ultrastructure and function in inner ear tissues. PMID:25016142

Bullen, A; Taylor, R R; Kachar, B; Moores, C; Fleck, R A; Forge, A

2014-09-01

405

Freeze mortality characteristics of the mold mite Tyrophagus putrescentiae, a significant pest of stored products.  

PubMed

The mold mite Tyrophagus putrescentiae (Shrank) is a common pest of stored food products. Until recently, commodity and facility treatments have relied on acaricides and fumigants to control this mite. However, T. putrescentiae will cause infestations in areas where acaricide or fumigant use may be restricted, prohibited, or highly impractical. Because temperature is an essential factor that limits the survival of arthropod species, extreme temperatures can be exploited as an effective method of control. Making low-temperature treatments reliable requires better temperature-time mortality estimates for different stages of this mite. This was accomplished by exposing a representative culture (eggs, nymphs, and adults) of noncold-acclimated T. putrescentiae to subfreezing temperatures to determine their supercooling points (SCPs), lower lethal temperatures (LLTs) and lethal times (LTimes) at set temperatures. The results indicate that the adult and nymphal stages of T. putrescentiae are freeze intolerant; based on 95% CIs, the adult LLT90 of -22.5 degrees C is not significantly different from the SCP of -24.2 degrees C and the nymphal LLT90 of -28.7 degrees C is not significantly different from the SCP of -26.5 degrees C. The egg stage seems to be freeze tolerant, with an LLT90 of -48.1 degrees C, significantly colder by approximately 13.5 degrees C than its SCP of -35.6 degrees C. The LTime demonstrates that 90% of all mite stages of T. putrescentiae can be controlled within commodity or packaged product by freezing to -18 degrees C for 5 h. By achieving the recommended time and temperature exposures, freezing conditions can be an effective way of controlling mites and reducing chronic infestations. PMID:21882712

Eaton, Marc; Kells, Stephen A

2011-08-01

406

Freezing Stress Response in Woody Tissues Observed Using Low-Temperature Scanning Electron Microscopy and Freeze Substitution Techniques 1  

PubMed Central

The objective of the current research was to examine the response of woody plant tissues to freezing stress by using scanning electron microscopy (SEM). Nonsupercooling species red osier dogwood (Cornus stolonifera Michx.), weeping willow (Salix babylonica L.), and corkscrew willow (Salix matsudana Koidz. f. tortuosa Rehd.) survived freezing stress as low as ?60°C. Cell collapse of ray parenchyma cells of these species was expected but did not occur. It was concluded that ray parenchyma cells of these species do not fit into either the supercooling or extracellular freezing classifications. Tissues from flowering dogwood (Cornus florida L.), apple (Malus domestica Borkh. cv “Starking III”), red oak (Quercus rubra L.), scarlet oak (Quercus coccinea Muench.), and red ash (Fraxinus pennsylvanica Marsh) were confirmed as supercooling species, and did not survive exposures below ?40°C. Ray parenchyma cells of these species did not collapse in response to freezing stress, as was expected. Cell collapse along the margins of voids were observed in bark of all seven species. Voids were the result of extracellular ice crystals formed in the bark during exposure to freezing stress. Tissues prepared by freeze substitution techniques were found to be adequately preserved when compared to those prepared by conventional fixation and low temperature SEM techniques. A freezing protocol for imposing freezing stress at temperatures lower than experienced naturally in the area where the study was conducted was developed that produced responses comparable to those observed in specimens collected in the field during natural freezing events. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:16668066

Malone, Stephen R.; Ashworth, Edward N.

1991-01-01

407

Genes, stress, and depression.  

PubMed

A relationship between genetic makeup and susceptibility to major depressive disorder (MDD) has long been suspected on the basis of family and twin studies. A metaanalysis of reports on the basis of twin studies has estimated MDD's degree of heritability to be 0.33 (confidence interval, 0.26-0.39). Among families exhibiting an increased prevalence of MDD, risk of developing the illness was enhanced in members exposed to a highly stressful environment. Aberrant genes can predispose to depression in a number of ways, for example, by diminishing production of growth factors that act during brain development. An aberrant gene could also increase or decrease a neurotransmitter's release into synapses, its actions, or its duration of activity. The gene products of greatest interest at present are those involved in the synthesis and actions of serotonin; among them, the serotonin-uptake protein localized within the terminals and dendrites of serotonin-releasing neurons. It has been found that the Vmax of platelet serotonin uptake is low in some patients with MDD; also, Vmax is highly correlated in twins. Antidepressant drugs such as the selective serotonin reuptake inhibitors act on this uptake protein. The specific genetic locus causing serotonin uptake to be lower in some patients with major depression involves a polymorphic region (5-HTTLPR) in the promoter region of the gene for the uptake protein. The gene itself exists as several alleles, the short "S" allele and the long "L" allele. The S variant is associated with less, and the L variant with more, of the uptake protein. The effect of stressful life events on depressive symptoms in young adults was found to be significantly stronger among SS or SL subjects than among LL subjects. Neuroimaging studies showed that people with the SS or SL alleles exhibited a greater activation of the amygdala in response to fearful stimuli than those with LL. It has been reported recently that mutations in the gene that controls serotonin synthesis in the human brain (tryptophan hydroxylase) also predispose to mood disturbances. It may be asked whether people who lack a psychiatric history should be advised to avoid stressful environments if they are found to carry the SS or SL alleles. PMID:15877307

Wurtman, Richard J

2005-05-01

408

Major depressive episodes with hypomanic symptoms are common among depressed outpatients  

Microsoft Academic Search

Depressive mixed states (major depressive episodes [MDE] with some hypomanic symptoms) are not classified in DSM-IV. The aim of the present study was to determine the prevalence of depressive mixed states in depressed outpatients, and to compare bipolar II with unipolar depressive mixed states. Seventy consecutive bipolar II and unipolar depressed outpatients were interviewed using the DSM-IV Structured Clinical Interview

Franco Benazzi

2001-01-01

409

The role of rumination in depressive disorders and mixed anxiety\\/depressive symptoms  

Microsoft Academic Search

Several studies have shown that people who engage in ruminative responses to depressive symptoms have higher levels of depressive symptoms over time, after accounting for baseline levels of depressive symptoms. The analyses reported here showed that rumination also predicted depressive disorders, including new onsets of depressive episodes. Rumination predicted chronicity of depressive disorders before accounting for the effects of baseline

Susan Nolen-Hoeksema

2000-01-01

410

Satellite freeze forecast system: Executive summary  

NASA Technical Reports Server (NTRS)

A satellite-based temperature monitoring and prediction system consisting of a computer controlled acquisition, processing, and display system and the ten automated weather stations called by that computer was developed and transferred to the national weather service. This satellite freeze forecasting system (SFFS) acquires satellite data from either one of two sources, surface data from 10 sites, displays the observed data in the form of color-coded thermal maps and in tables of automated weather station temperatures, computes predicted thermal maps when requested and displays such maps either automatically or manually, archives the data acquired, and makes comparisons with historical data. Except for the last function, SFFS handles these tasks in a highly automated fashion if the user so directs. The predicted thermal maps are the result of two models, one a physical energy budget of the soil and atmosphere interface and the other a statistical relationship between the sites at which the physical model predicts temperatures and each of the pixels of the satellite thermal map.

Martsolf, J. D. (principal investigator)

1983-01-01

411

Adaptation to seasonality and the winter freeze.  

PubMed

Flowering plants initially diversified during the Mesozoic era at least 140 million years ago in regions of the world where temperate seasonal environments were not encountered. Since then several cooling events resulted in the contraction of warm and wet environments and the establishment of novel temperate zones in both hemispheres. In response, less than half of modern angiosperm families have members that evolved specific adaptations to cold seasonal climates, including cold acclimation, freezing tolerance, endodormancy, and vernalization responsiveness. Despite compelling evidence for multiple independent origins, the level of genetic constraint on the evolution of adaptations to seasonal cold is not well understood. However, the recent increase in molecular genetic studies examining the response of model and crop species to seasonal cold offers new insight into the evolutionary lability of these traits. This insight has major implications for our understanding of complex trait evolution, and the potential role of local adaptation in response to past and future climate change. In this review, we discuss the biochemical, morphological, and developmental basis of adaptations to seasonal cold, and synthesize recent literature on the genetic basis of these traits in a phylogenomic context. We find evidence for multiple genetic links between distinct physiological responses to cold, possibly reinforcing the coordinated expression of these traits. Furthermore, repeated recruitment of the same or similar ancestral pathways suggests that land plants might be somewhat pre-adapted to dealing with temperature stress, perhaps making inducible cold traits relatively easy to evolve. PMID:23761798

Preston, Jill C; Sandve, Simen R

2013-01-01

412

Component stress during freeze/thaw cycling  

SciTech Connect

During the past year, the feasibility and usefulness of mathematically modeling the processes occurring in Na/S cells during freeze/thaw (F/T) cycling has been demonstrated with the identification of potential stress producing phenomena. The first strain measurements on functioning cells have been completed that have shown the variable nature of the positive-electrode materials, a factor that may account for the randomness of actual F/T induced failures. Physical property measurements have quantified the important effect the presence of the graphite felt can have on Young's modulus for sulfur. With the completion of the physical-property and strain measurements in the coming year, final modification will be made to the material models contained in the thermo-mechanical code. The strain data will be used to validate the accuracy of the component stress calculations. Once validated, this code can be used to identify and simulate important aspects of various design options and to determine the feasiblity of proposed failure mechanisms. 4 refs., 10 figs., 1 tab.

Braithwaite, J.W.; Subia, S.R.; Stone, C.M.; Hammetter, W.F.

1988-05-23

413

Component stress during freeze/thaw cycling  

NASA Astrophysics Data System (ADS)

During the past year, the feasibility and usefulness of mathematically modeling the processes occurring in Na/S cells during freeze/thaw (F/T) cycling has been demonstrated with the identification of potential stress producing phenomena. The first strain measurements on functioning cells have been completed that have shown the variable nature of the positive-electrode materials, a factor that may account for the randomness of actual F/T induced failures. Physical property measurements have quantified the important effect the presence of the graphite felt can have on Young's modulus for sulfur. With the completion of the physical-property and strain measurements in the coming year, final modification will be made to the material models contained in the thermo-mechanical code. The strain data will be used to validate the accuracy of the component stress calculations. Once validated, this code can be used to identify and simulate important aspects of various design options and to determine the feasibility of proposed failure mechanisms.

Braithwaite, J. W.; Subia, S. R.; Stone, C. M.; Hammetter, W. F.

1988-05-01

414

Hot water can freeze faster than cold?!?  

E-print Network

We review the Mpemba effect, where intially hot water freezes faster than initially cold water. While the effect appears impossible at first sight, it has been seen in numerous experiments, was reported on by Aristotle, Francis Bacon, and Descartes, and has been well-known as folklore around the world. It has a rich and fascinating history, which culminates in the dramatic story of the secondary school student, Erasto Mpemba, who reintroduced the effect to the twentieth century scientific community. The phenomenon, while simple to describe, is deceptively complex, and illustrates numerous important issues about the scientific method: the role of skepticism in scientific inquiry, the influence of theory on experiment and observation, the need for precision in the statement of a scientific hypothesis, and the nature of falsifiability. We survey proposed theoretical mechanisms for the Mpemba effect, and the results of modern experiments on the phenomenon. Studies of the observation that hot water pipes are more likely to burst than cold water pipes are also described.

Monwhea Jeng

2005-12-29

415

Adaptation to seasonality and the winter freeze  

PubMed Central

Flowering plants initially diversified during the Mesozoic era at least 140 million years ago in regions of the world where temperate seasonal environments were not encountered. Since then several cooling events resulted in the contraction of warm and wet environments and the establishment of novel temperate zones in both hemispheres. In response, less than half of modern angiosperm families have members that evolved specific adaptations to cold seasonal climates, including cold acclimation, freezing tolerance, endodormancy, and vernalization responsiveness. Despite compelling evidence for multiple independent origins, the level of genetic constraint on the evolution of adaptations to seasonal cold is not well understood. However, the recent increase in molecular genetic studies examining the response of model and crop species to seasonal cold offers new insight into the evolutionary lability of these traits. This insight has major implications for our understanding of complex trait evolution, and the potential role of local adaptation in response to past and future climate change. In this review, we discuss the biochemical, morphological, and developmental basis of adaptations to seasonal cold, and synthesize recent literature on the genetic basis of these traits in a phylogenomic context. We find evidence for multiple genetic links between distinct physiological responses to cold, possibly reinforcing the coordinated expression of these traits. Furthermore, repeated recruitment of the same or similar ancestral pathways suggests that land plants might be somewhat pre-adapted to dealing with temperature stress, perhaps making inducible cold traits relatively easy to evolve. PMID:23761798

Preston, Jill C.; Sandve, Simen R.

2013-01-01

416

Freeze protection valve for solar heaters  

SciTech Connect

This patent describes a solar heater freeze protection valve apparatus comprising in combination: a valve housing; a remote sensor operatively connected to the valve housing from a remote position, the remote sensor including a bulb containing a liquid adapted to compress and expand with the temperature adjacent the bulb; a piston located in the valve body and slidable responsive to expansion and contraction of the liquid in the remote sensor; a first valve element located in the valve housing and attached to the valve piston for movement; a second valve element located in the valve housing and attached to the housing; a first valve seat in the second valve element forming an opening; a second valve seat positioned in a water passageway to allow the flow of fluid when the second valve element is in an open position and to cut off the flow of fluid when the second valve element is in a closed position. Liquid in a solar heater flows at predetermined temperature readings; and the second valve element is biased in one direction and has a second opening to increase the pressure therebehind when the first valve element closes on the first valve seat. The second valve element closes on the second valve seat.

Cromer, C.J.

1987-07-21

417

Anger Attacks in Depression – Evidence for a Male Depressive Syndrome  

Microsoft Academic Search

Background: It has been proposed that aggression and especially anger attacks play an important role in the symptomatology of depression. Furthermore, it has been hypothesized that these symptoms are more prevalent in males than in females. Methods: We conducted a study in 217 depressed patients (104 females, 113 males) without psychiatric comorbidity using questionnaires. Study subjects had previously been treated

Dietmar Winkler; Edda Pjrek; Siegfried Kasper

2005-01-01

418

Condensation and freezing of droplets on superhydrophobic surfaces.  

PubMed

Superhydrophobic coatings are reported as promising candidates for anti-icing applications. Various studies have shown that as well as having ultra water repellency the surfaces have reduced ice adhesion and can delay water freezing. However, the structure or texture (roughness) of the superhydrophobic surface is subject to degradation during the thermocycling or wetting process. This degradation can impair the superhydrophobicity and the icephobicity of those coatings. In this review, a brief overview of the process of droplet freezing on superhydrophobic coatings is presented with respect to their potential in anti-icing applications. To support this discussion, new data is presented about the condensation of water onto physically decorated substrates, and the associated freezing process which impacts on the freezing of macroscopic droplets on the surface. PMID:24200089

Oberli, Linda; Caruso, Dean; Hall, Colin; Fabretto, Manrico; Murphy, Peter J; Evans, Drew

2014-08-01

419

Normal freezing of ideal ternary systems of the pseudobinary type  

NASA Technical Reports Server (NTRS)

Perfect liquid mixing but no solid diffusion is assumed in normal freezing. In addition, the molar compositions of the freezing solid and remaining liquid, respectively, follow the solidus and liquidus curves of the constitutional diagram. For the linear case, in which both the liquidus and solidus are perfectly straight lines, the normal freezing equation giving the fraction solidified at each melt temperature and the solute concentration profile in the frozen solid was determined as early as 1902, and has since been repeatedly published. Corresponding equations for quadratic, cubic or higher-degree liquidus and solidus lines have also been obtained. The equation of normal freezing for ideal ternary liquid solutions solidified into ideal solid solutions of the pseudobinary type is given. Sample computations with the use of this new equation were made and are given for the Ga-Al-As system.

Li, C. H.

1972-01-01

420

Phase separation during freezing upon warming of aqueous solutions  

NASA Astrophysics Data System (ADS)

Using differential scanning calorimetry, we show that the addition of solute(s) to emulsified water lowers the freezing temperature to <231 K, the homogeneous nucleation temperature of pure bulk water, or even completely suppresses freezing. In the latter case, freezing upon warming occurs above TX ? 150 K and leads to a phase separation into pure ice and a freeze-concentrated solution (FCS) which crystallizes upon further warming. We also show that emulsified 20-21.5 wt. % HCl solutions and the FCS of HCl/H2O solutions transform to glass at Tg ? 127-128 K, i.e., lower than Tg ? 136 K of water. We suggest that water nanodrops adsorbed on fumed silica resemble bulk water more than water confined in nanoscaled confinement and also more than nanoscaled water domains in aqueous solution.

Bogdan, A.; Loerting, T.

2014-11-01

421

even without a freeze plants can be damaged.  

E-print Network

, orchids as well as many aroids, succulent plants and Amazon lilies. It is worth considering movable of water (e.g. a man-made lake ­ heat stored in water and released during a radiational freeze can help

Jawitz, James W.

422

On deriving flux freezing in magnetohydrodynamics by direct differentiation  

NASA Astrophysics Data System (ADS)

The magnetic flux freezing theorem is a basic principle of ideal magnetohydrodynamics (MHD), a commonly used approximation to describe the aspects of astrophysical and laboratory plasmas. The theorem states that the magnetic flux—the integral of magnetic field penetrating a surface—is conserved in time as that surface is distorted in time by fluid motions. Pedagogues of MHD commonly derive flux freezing without showing how to take the material derivative of a general flux integral and/or assuming a vanishing field divergence from the outset. Here I avoid these shortcomings and derive flux freezing by direct differentiation, explicitly using a Jacobian to transform between the evolving field-penetrating surface at different times. The approach is instructive for its generality and helps elucidate the role of magnetic monopoles in breaking flux freezing. The paucity of appearances of this derivation in standard MHD texts suggests that its pedagogic value is underappreciated.

Blackman, Eric G.

2013-03-01

423

Multiphoton imaging of biological samples during freezing and heating  

NASA Astrophysics Data System (ADS)

We applied multiphoton microscopic imaging to observe freezing and heating effects in plant- and animal cell samples. The experimental setups consisted of a multiphoton imaging system and a heating and cooling stage which allows for precise temperature control from liquid nitrogen temperature (-196°C 77 K) up to +600°C (873 K) with heating/freezing rates between 0.01 K/min and 150 K/min. Two multiphoton imaging systems were used: a system based on a modified optical microscope and a flexible mobile system. To illustrate the imaging capabilities, plant leafs as well as animal cells were microscopically imaged in vivo during freezing based on autofluorescence lifetime and intensity of intrinsic molecules. The measurements illustrate the usefulness of multiphoton imaging to investigate freezing effects on animal and plant cells.

Breunig, H. G.; Uchugonova, A.; König, K.

2014-02-01

424

ARCTIC FOUNDATIONS, INC. FREEZE BARRIER SYSTEM - SITE TECHNOLOGY CAPSULE  

EPA Science Inventory

Arctic Foundations, Inc. (AFI), of Anchorage, Alaska has developed a freeze barrier technology designed to prevent the migration of contaminants in groundwater by completely isolating contaminant source areas until appropriate remediation techniques can be applied. With this tec...

425

ARCTIC FOUNDATIONS, INC. FREEZE BARRIER TECHNOLOGY; INNOVATIVE TECHNOLOGY EVALUATION REPORT  

EPA Science Inventory

Arctic Foundations, Inc. (AFI), of Anchorage, Alaska has developed a freeze barrier technology designed to prevent the migration of contaminants in groundwater by completely isolating contaminant source areas until appropriate remediation techniques can be applied. With this tech...

426

Physicothermal Properties of Freeze-Dried Fish Oil Nanocapsules Frozen under Different Conditions  

Microsoft Academic Search

This research compared the effects of vacuum freeze drying (VFD) and conventional freeze drying (CFD) processes on the stability of fish oil–loaded nanocapsules (NCs). For CFD, the NCs showed aggregation that was dependent on the freezing temperature. The encapsulation efficiency of CFD was greater than that of VFD, except at the freezing temperature of ?30°C. From differential scanning calorimetry (DSC)

Piyawan Bejrapha; Sang-Gi Min; Suvimol Surassmo; Mi-Jung Choi

2010-01-01

427

Xylem cavitation caused by drought and freezing stress in four co-occurring Juniperus species  

E-print Network

Xylem cavitation caused by drought and freezing stress in four co-occurring Juniperus species induced by drought but in many cases, not by freezing. Rarely have vulnerability to drought and freezing and distribution of plants in many regions of the world. We studied vulnerability to drought- and freezing- induced

Jackson, Robert B.

428

Prediction of Freezing Times for Regular Multidimensional Foods using Simple Formulae  

Microsoft Academic Search

Freezing is a widely used food preservation technique. The designers and users of freezing equipment need simple prediction methods to calculate the process time. The objective of the present work was to extend the use of a simple prediction method, developed for the freezing of uni-dimensional foods, to the prediction of the freezing times of regular multi-dimensional foods, using different

V. O. Salvadori; A. De Michelis; R. H. Mascheroni

1997-01-01

429

Biphasic Investigation of Tissue Mechanical Response During Freezing Front Propagation  

PubMed Central

Cryopreservation of engineered tissue (ET) has achieved limited success due to limited understanding of freezing-induced biophysical phenomena in ETs, especially fluid-matrix interaction within ETs. To further our understanding of the freezing-induced fluid-matrix interaction, we have developed a biphasic model formulation that simulates the transient heat transfer and volumetric expansion during freezing, its resulting fluid movement in the ET, elastic deformation of the solid matrix and the corresponding pressure redistribution within. Treated as a biphasic material, the ET consists of a porous solid matrix fully saturated with interstitial fluid. Temperature-dependent material properties were employed and phase change was included by incorporating the latent heat of phase change into an effective specific heat term. Model-predicted temperature distribution, the location of the moving freezing front, and the ET deformation rates through the time course compare reasonably well with experiments reported previously. Results from our theoretical model show that behind the marching freezing front, the ET undergoes expansion due to phase change of its fluid contents. It compresses the region preceding the freezing front leading to its fluid expulsion and reduced regional fluid volume fractions. The expelled fluid is forced forward and upward into the region further ahead of the compression zone causing a secondary expansion zone; which then compresses the region further downstream with much reduced intensity. Overall, it forms an alternating expansion-compression pattern which moves with the marching freezing front. The present biphasic model helps us to gain insights into some facets of the freezing process and cryopreservation treatment that could not be gleaned experimentally. Its resulting understanding will ultimately be useful to design and improve cryopreservation protocols for ETs. PMID:22757502

Wright, Jamie; Han, Bumsoo; Chuong, Cheng-Jen

2012-01-01

430

Yukon River ice: freeze-up data (1883-1975)  

SciTech Connect

Freeze-up observations have been sporadically collected on the Yukon River since the late 19th century. This report contains data from 29 different locations on the river; the earliest observations were made in 1883. The purpose is to compile all the presently known data on the freeze-up of the Yukon River for use in future scientific studies and engineering reports. 6 refs.

Fountain, A.G.; Vaughn, B.H.

1984-01-01

431

Freeze concentration of dairy products Phase 2. Final report  

SciTech Connect

An efficient, electrically driven freeze concentration system offers potential for substantially increasing electricity demand while providing the mature dairy industry with new products for domestic and export markets together with enhanced production efficiencies. Consumer tests indicate that dairy products manufactured from freeze-concentrated ingredients are either preferred or considered equivalent in quality to fresh milk-based products. Economic analyses indicate that this technology should be competitive with thermal evaporation processes on a commercial basis.

Best, D.E.; Vasavada, K.C.

1993-09-01

432

Three keys to the radiation of angiosperms into freezing environments.  

PubMed

Early flowering plants are thought to have been woody species restricted to warm habitats. This lineage has since radiated into almost every climate, with manifold growth forms. As angiosperms spread and climate changed, they evolved mechanisms to cope with episodic freezing. To explore the evolution of traits underpinning the ability to persist in freezing conditions, we assembled a large species-level database of growth habit (woody or herbaceous; 49,064 species), as well as leaf phenology (evergreen or deciduous), diameter of hydraulic conduits (that is, xylem vessels and tracheids) and climate occupancies (exposure to freezing). To model the evolution of species' traits and climate occupancies, we combined these data with an unparalleled dated molecular phylogeny (32,223 species) for land plants. Here we show that woody clades successfully moved into freezing-prone environments by either possessing transport networks of small safe conduits and/or shutting down hydraulic function by dropping leaves during freezing. Herbaceous species largely avoided freezing periods by senescing cheaply constructed aboveground tissue. Growth habit has long been considered labile, but we find that growth habit was less labile than climate occupancy. Additionally, freezing environments were largely filled by lineages that had already become herbs or, when remaining woody, already had small conduits (that is, the trait evolved before the climate occupancy). By contrast, most deciduous woody lineages had an evolutionary shift to seasonally shedding their leaves only after exposure to freezing (that is, the climate occupancy evolved before the trait). For angiosperms to inhabit novel cold environments they had to gain new structural and functional trait solutions; our results suggest that many of these solutions were probably acquired before their foray into the cold. PMID:24362564

Zanne, Amy E; Tank, David C; Cornwell, William K; Eastman, Jonathan M; Smith, Stephen A; FitzJohn, Richard G; McGlinn, Daniel J; O'Meara, Brian C; Moles, Angela T; Reich, Peter B; Royer, Dana L; Soltis, Douglas E; Stevens, Peter F; Westoby, Mark; Wright, Ian J; Aarssen, Lonnie; Bertin, Robert I; Calaminus, Andre; Govaerts, Rafaël; Hemmings, Frank; Leishman, Michelle R; Oleksyn, Jacek; Soltis, Pamela S; Swenson, Nathan G; Warman, Laura; Beaulieu, Jeremy M

2014-02-01

433

Correlation estimates ethane plant's carbon-dioxide freezing pressure  

Microsoft Academic Search

This paper describes a new correlation model which allows quick calculation of the expected COâ freezing pressure in a turboexpander ethane extraction plant. It presents a program for use with the TI-58 calculator which incorporates the correlation equations. If the recommended 2,750 kPa minimum COâ freezing pressure is applied, then 73% ethane recovery is the maximum level that could safely

Trebble

1983-01-01

434

Effect of air voids on salt scaling and internal freezing  

Microsoft Academic Search

By combining calorimetric measurements with dilatometry, it has been possible to calculate the contributions of thermal expansion, pore pressure, and crystallization pressure of ice to the strain observed in a mortar during freezing\\/thawing cycles. Air-entrained mortars contract upon freezing, while non-air-entrained mortars expand. The expansion of the latter is attributed primarily to hydraulic pressure, owing to the rapid growth of

Zhenhua Sun; George W. Scherer

2010-01-01

435

A Counselor's Primer on Postpartum Depression.  

ERIC Educational Resources Information Center

Notes that women are particularly vulnerable to depression during the postpartum period. Distinguishes postpartum depression from normal postpartum adjustment, postpartum blues, and postpartum psychosis. Describes biological, psychodynamic, and diathesis-stress perspectives on postpartum depression. Encourages counselors to fashion individualized…

Pfost, Karen S.; And Others

1990-01-01

436

How Do Fundamental Christians Deal with Depression?  

ERIC Educational Resources Information Center

Provides explanation of developmental dynamics in experience of fundamental Christians that provoke reactive depression. Describes depressant retardant defenses against depression that have been observed in Christian fundamental subculture. Suggests four counseling strategies for helping fundamentalists. (Author/ABL)

Spinney, Douglas Harvey

1991-01-01

437

[A psychosocial perspective of depressive symptoms in adolescence].  

PubMed

This study aimed at understanding the social representations (SR) of depression among adolescents on high school level. Two hundred and twenty-two (222) adolescents of both sexes (53% male and 47% female), aged between 14 and 19 years and attending the first, second and third grades of high school participated in the study. The instruments used were: the Beck Depression Inventory (BDI) for selecting the sample, using 17 as a cut point. The adolescents who achieved this score were invited to participate in the second part of this study consisting of semi-structured interviews and application of Free Association Tests with the stimulus words: depression, depressed person and me. It was verified that the adolescents anchored their SR of depression as synonym for pain, grief, misfortune, hatred, death, discouragement, anxiety, solitude and tears. The SR elaborated by the social actors of this study revealed a similarity with the conception/description, as described in psychiatry. The purpose of this study besides helping to understand the suffering provoked by depressive symptoms is to contribute to a better quality of life of these adolescents. PMID:19197415

Aragão, Thais Araújo; Coutinho, Maria da Penha de Lima; de Araújo, Ludgleydson Fernandes; Castanha, Alessandra Ramos

2009-01-01

438

Composition-dependent freezing nucleation rates for HNO3/H2O aerosols resembling gravity-wave-perturbed stratospheric particles  

NASA Astrophysics Data System (ADS)

Laboratory measurements are presented for the freezing kinetics of H2O/HNO3 aerosols over the temperature range of 188-204 K. For 2:1 H2O:HNO3 aerosols crystallizing to NAD we observed a maximum nucleation rate of J = 9.3×109 cm-3 s-1 at 194 K. This temperature is between the glass point of 161 K [Ji et al., 1993] and the melting point of 235.5 K [Ji et al., 1996]. This can be compared to a previous measurement of J = 6.7×109 cm-3 s-1 at 193 K [Disselkamp et al., 1996] and lower temperature measurements of J ? 1010-1012 cm-3 s-1 at 178.8 - 175.8 K [Bertram and Sloan, 1998a]. Measured nucleation rates decrease as the aerosol becomes dilute, but NAD formation is still observable for 2.5:1 H2O:HNO3 at temperatures near 195 K. In contrast, freezing of 3:1 H2O:HNO3 aerosol was not observed for constant temperature experiments throughout this temperature range, yielding an upper limit of J<1.5×109 cm-3 s-1. This is the lowest experimental value determined for 3:1 H2O:HNO3 freezing rates at these temperatures. From the measured freezing rates and knowledge of the free energy of diffusion the average interfacial free energy for NAD in a 2:1 H2O:HNO3 solution was determined to be ? = 25.2 ergs cm-2. A limit for the interfacial free energy was placed on 3:1 H2O:HNO3 particles, for which freezing was not observed. These data imply that if aerosols reach compositions more concentrated than 3:1 H2O:HNO3 in the atmosphere, NAD may play a role in polar stratospheric cloud formation.

Prenni, Anthony J.; Onasch, Timothy B.; Tisdale, Robert T.; Siefert, Ronald L.; Tolbert, Margaret A.

1998-11-01

439

Cobalt-Carbon Eutectic Fixed Point for Contact Thermometry  

NASA Astrophysics Data System (ADS)

Two Co-C eutectic fixed points were constructed for thermocouple calibration. The eutectic fixed points were measured with a Pt/Pd thermocouple calibrated at the freezing temperatures of Sn, Zn, Al, Ag, and Au. A temperature of (1323.99 ± 0.52) °C ( k = 2) was determined via this method. The cell design allowed filling to be accomplished in a single step. Each cell was held above 1300 °C for at least 42 h and was subjected to at least 20 melt/freeze cycles with no mechanical failure occurring.

Todd, A. D. W.; Gotoh, M.; Woods, D. J.; Hill, K. D.

2011-01-01

440

Help-Seeking Behaviors among Chinese Americans with Depressive Symptoms  

ERIC Educational Resources Information Center

An exploratory survey indicated that the depression prevalence among Chinese Americans is 17.4 percent. Of 516 respondents, 34.9 percent preferred seeking advice from friends or relatives, followed by 30.2 percent not showing any preference when facing a mental health problem. Logistic regression results pointed to three contributing factors:…

Leung, Patrick; Cheung, Monit; Tsui, Venus

2012-01-01

441

Epidemiological Perspectives on Maternal Depression and the Young Child.  

ERIC Educational Resources Information Center

Reviews epidemiological studies on the prevalence of maternal depression in the general population and the social etiology of behavioral and psychiatric disorders in early childhood. Also reports an original study conducted in Martha's Vineyard and points out avenues for much-needed further research in this area. (BB)

Garrison, William T.; Earls, Felton J.

1986-01-01

442

Freezing of barley studied by infrared video thermography.  

PubMed

Freezing of barley (Hordeum vulgare), Hordeum murinum, and Holcus lanatus was studied using infrared video thermography. In the field, ice could enter H. lanatus leaves through hydathodes. In laboratory tests with barley, initially 0.4% of the leaf water froze, spreading in alternate strips of high and low freezing intensity longitudinally at 1 to 4 cm s(-1), and simultaneously spreading laterally at 0.3 cm s(-1). Similar results were obtained in the field with H. lanatus. A distinct second, more intense, freezing event spread slowly from the margins of the leaves toward the midrib. Organs of uprooted barley tested in the laboratory froze in this order: nucleated leaf, roots, older leaves, younger leaves, and secondary tillers. When ice spread from one leaf to the rest of the plant the crown delayed spread to the roots and other leaves. There was a longer delay above than below -2 degrees C, helping to protect the crown from freezing during mild frosts. Initial spread of freezing was not damaging. However, the initial spread is a prerequisite for the second freezing event, which can cause damage. The route of the initial spread of ice may be extracellular, drawing water from more gel-like parts of the cell wall. PMID:11154332

Pearce, R S; Fuller, M P

2001-01-01

443

Tissue Triage and Freezing for Models of Skeletal Muscle Disease  

PubMed Central

Skeletal muscle is a unique tissue because of its structure and function, which requires specific protocols for tissue collection to obtain optimal results from functional, cellular, molecular, and pathological evaluations. Due to the subtlety of some pathological abnormalities seen in congenital muscle disorders and the potential for fixation to interfere with the recognition of these features, pathological evaluation of frozen muscle is preferable to fixed muscle when evaluating skeletal muscle for congenital muscle disease. Additionally, the potential to produce severe freezing artifacts in muscle requires specific precautions when freezing skeletal muscle for histological examination that are not commonly used when freezing other tissues. This manuscript describes a protocol for rapid freezing of skeletal muscle using isopentane (2-methylbutane) cooled with liquid nitrogen to preserve optimal skeletal muscle morphology. This procedure is also effective for freezing tissue intended for genetic or protein expression studies. Furthermore, we have integrated our freezing protocol into a broader procedure that also describes preferred methods for the short term triage of tissue for (1) single fiber functional studies and (2) myoblast cell culture, with a focus on the minimum effort necessary to collect tissue and transport it to specialized research or reference labs to complete these studies. Overall, this manuscript provides an outline of how fresh tissue can be effectively distributed for a variety of phenotypic studies and thereby provides standard operating procedures (SOPs) for pathological studies related to congenital muscle disease. PMID:25078247

Meng, Hui; Janssen, Paul M.L.; Grange, Robert W.; Yang, Lin; Beggs, Alan H.; Swanson, Lindsay C.; Cossette, Stacy A.; Frase, Alison; Childers, Martin K.; Granzier, Henk; Gussoni, Emanuela; Lawlor, Michael W.

2014-01-01

444

Influence of Depressive Symptoms on Dopaminergic Treatment of Parkinson’s Disease  

PubMed Central

Introduction: Depressive symptoms are very common in patients with Parkinson’s disease (PD) and have a significant impact on the quality of life. Dopaminergic medication has been shown to have an influence on the development of depressive symptoms. Materials and methods: The present study analyzed two groups of non-demented patients with PD, with and without depressive symptoms, and reported the correlations between antiparkinsonian medication [specifically levodopa (l-DOPA) and dopaminergic agonists] with depressive symptoms. Results: A strong statistically significant positive correlation between l-DOPA dosages and the level of depressive symptoms has been revealed, suggesting that higher l-DOPA dosages correlate with a worsening of depressive status. No significant correlation was found with dopamine agonists. Discussion: The results of this study show that in patients with PD, higher l-DOPA dosages correlate with worse depressive symptoms. From this point of view, PD patients need to be better diagnosed with respect to depressive symptoms and need additional treatment adjustment when clinical manifestations of depression are present. Clinicians must be aware that dopaminergic drugs are not sufficient to alleviate depressive symptoms. PMID:25309508

Hanganu, Alexandru; Degroot, Clotilde; Monchi, Oury; Bedetti, Christophe; Mejia-Constain, Béatriz; Lafontaine, Anne-Louise; Chouinard, Sylvain; Bruneau, Marie-Andrée

2014-01-01

445

No association between dietary patterns and depressive symptoms among a community-dwelling population in Japan  

PubMed Central

Background Studies of the associations between diet and depression have primarily focused on single nutrients or foods. Recently, dietary patterns representing a combination of foods have attracted more interest than individual nutrient. The objective of this study was to examine the association between dietary patterns and depressive symptoms among a community-dwelling population in Japan. Methods We examined the association between dietary patterns and the risk of depression among 791 Japanese community-dwelling individuals. Diet was assessed with a validated brief-type self-administered diet history questionnaire (BDHQ). Dietary patterns from 52 predefined food groups [energy-adjusted food (g/d)] were extracted by principal component analysis. The Center for Epidemiologic Studies Depression Scale (CES-D) with a cut-off point of 16 was used to assess the prevalence of depression. Results A total of 97 subjects (12.3%) were classified as having depression. Four dietary patterns were identified: “Healthy”, “Western”, “Bread and confectionery”, and “Alcohol and accompanying” dietary patterns. After adjusting for potential confounders, the dietary patterns were not related to the risk of depression. Conclusions The present study failed to find associations between dietary patterns and the risk of depression. However, the interpretation of our results was hampered by the lack of certain data, including employment physical activity and longitudinal observations. Potential associations between dietary patterns and depressive symptoms were not completely ruled out. Future research exploring dietary patterns and depressive symptoms is warranted. PMID:23006931

2012-01-01

446

Sleep and Quality of Life in Depression  

Microsoft Academic Search

Major depression is a common disorder; nearly 10% of the population suffers from a depressive illness in any given year. There\\u000a is a strong association between sleep disturbances and depression. The most common sleep disturbance associated with major\\u000a depressive disorder is insomnia. The relationship between insomnia and depression is bidirectional in that insomnia is one\\u000a of the symptoms of depression

Okan Caliyurt

447

Postpartum depression in primiparous parents  

Microsoft Academic Search

Investigated the hypothesis that postpartum depression is a function of disruption of parents' prepartum functioning by the subsequent demands of infant caretaking. 78 primiparous middle SES married couples (mean age 25.5 yrs) completed a battery of questionnaires, including the Beck Depression Inventory, at 8 wks prepartum and 8 wks postpartum, assessing indicators of stress related to childcare. Results indicate that

A. Kathleen Atkinson; Annette U. Rickel

1984-01-01

448

Increased Spreading Activation in Depression  

ERIC Educational Resources Information Center

The dopaminergic system is implicated in depressive disorders and research has also shown that dopamine constricts lexical/semantic networks by reducing spreading activation. Hence, depression, which is linked to reductions of dopamine, may be associated with increased spreading activation. However, research has generally found no effects of…

Foster, Paul S.; Yung, Raegan C.; Branch, Kaylei K.; Stringer, Kristi; Ferguson, Brad J.; Sullivan, William; Drago, Valeria

2011-01-01

449

Left frontal hypoactivation in depression  

Microsoft Academic Search

Baseline resting electroencephalogram activity was recorded with 3 different reference montages from 15 clinically depressed and 13 control subjects. Power in all frequency bands was extracted by fast Fourier transformation. There was a significant Group  Hemisphere interaction in the mid- frontal region, for the alpha band power only. Depressed subjects had less left-sided activation (i.e., more alpha activity) than

Jeffrey B. Henriques; Richard J. Davidson

1991-01-01

450

Postpartum Depression Causes and Correlates  

Microsoft Academic Search

A variety of explanations have been suggested to explain postpartum depression in women, including biological, psychological, social and cultural forces (Fossey, Papiernik & Bydlowski, 1987; O'Hara & Swain, 1996). This paper goes beyond biological explanations to explore psychosocial influences such as the cultural experience of giving birth, maternal expectations and the role of social support. Postpartum depression rates in Germany

Tracie Merritt; Sara Kuppin; Michelle Wolper; Bruce B. Downs

451

Clinical Inertia in Depression Treatment  

PubMed Central

Objective To explore reasons for clinical inertia in the management of persistent depression symptoms. Research Design We characterized patterns of treatment adjustment in primary care and their relation to the patient’s clinical condition by modeling transition to a given treatment “state” conditional upon the current state of treatment. We assessed associations of patient, clinician, and practice barriers with adjustment decisions. Subjects Survey data on patients in active care for major depression was collected at six-month intervals over a two-year period for the Quality Improvement for Depression (QID) studies. Measures Patient and clinician characteristics were collected at baseline. Depression severity and treatment were measured at each interval. Results Approximately one-third of the observation periods ending with less than a full response resulted in an adjustment recommendation. Clinicians often respond correctly to the combination of severe depression symptoms and less than maximal treatment by changing the treatment. Appropriate adjustment is less common, however, in management of less severely depressed patients who do not improve after starting treatment, particularly if their care already meets minimal treatment intensity guidelines. Conclusions Our findings suggest that quality improvement efforts should focus on promoting appropriate adjustments for patients with persistent depression symptoms, particularly those with less severe depression. PMID:19704353

Henke, Rachel M.; Zaslavsky, Alan M.; McGuire, Thomas G.; Ayanian, John Z.; Rubenstein, Lisa V.

2014-01-01

452

Parental Depression and Child Disturbance.  

ERIC Educational Resources Information Center

Families in which one or both parents are diagnosed as being depressed are observed in this ongoing study of how the behavior of depressed parents relates to the child's present and long-term development. Each family which enters the study has a child approximately two years old and a child between five and seven years old. Families are initially…

Radke-Yarrow, Marian

453

Etiology of Depression in Children  

ERIC Educational Resources Information Center

Major Depressive Disorder (MDD) is experienced by a significant proportion of youth today, occurring at an earlier age than found in previous generations. Major Depressive Disorder can produce long-lasting detrimental effects on a child's life, which raises the question of etiology. Three areas were examined for evidence identifying specific…

Watts, Shirley J.; Markham, Ramona A.

2005-01-01

454

Depression during the Menopausal Transition  

ERIC Educational Resources Information Center

The perception that menopause leads to mood disturbances such as depression has a long history. How did these beliefs come about, and are they supported by the scientific literature? This article reviews the theories of menopause and depression, the scientific literature, and the implications of these findings for prevention and treatment.…

Avis, Nancy E.

2003-01-01

455

Adolescent depression. Part 1. Diagnosis.  

PubMed Central

Clinical depression among adolescents results in significant morbidity, including somatic distress and impaired cognitive, interpersonal, and academic functioning. Risk factors are clearly identifiable, and family physicians should have a high index of suspicion. Depression is the primary risk factor for adolescent suicide. PMID:7920051

Garland, E. J.

1994-01-01

456

Ultrastructure of hypertrophic cartilage: histochemical procedures compared with high pressure freezing and freeze substitution.  

PubMed

The effect of cationic dyes on the ultrastructure of hypertrophic cartilage was compared with results obtained with modern cryotechniques in studies on rat epiphyseal growth plate. Addition of alcian blue, acridine orange, cupromeronic blue, ruthenium hexamine trichloride, ruthenium red, or safranin O to conventional glutaraldehyde/osmium tetroxide fixatives to a large extent resulted in prevention of chondrocyte shrinkage except for alcian blue which showed poor tissue penetration. The fine structure of the matrix in pericellular and territorial compartments appeared very coarse with areas of high contrast in tissue exposed to fixatives containing cationic dyes. This indicates structural collapse and precipitation of electron-dense material, a pattern clearly differing from that observed in specimens prepared by the cryotechniques. The dyes giving a pattern most similar to that seen after high pressure freezing, freeze substitution, and low temperature embedding were acridine orange and safranin O. It is concluded that studies of matrix ultrastructure down to the molecular level necessitate the application of cryotechniques. PMID:7529658

Engfeldt, B; Reinholt, F P; Hultenby, K; Widholm, S M; Müller, M

1994-10-01

457

Imaging the Endothelial Glycocalyx In Vitro by Rapid Freezing/Freeze Substitution Transmission Electron Microscopy  

PubMed Central

Objective Recent publications questioned the validity of endothelial cell (EC) culture studies of glycocalyx (GCX) function, due to findings that GCX in vitro may be substantially thinner than in vivo. The assessment of thickness differences is complicated by GCX collapse during dehydration for traditional electron microscopy. We measured in vitro GCX thickness using rapid freezing/freeze substitution transmission electron microscopy (RF/FS-TEM), taking advantage of high spatial resolution provided by TEM and the capability to stably preserve the GCX in its hydrated configuration by RF/FS. Methods and Results Bovine aortic and rat fat pad endothelial cells (BAEC and RFPEC) were subjected to conventional- or RF/FS-TEM. Conventionally preserved BAEC GCX was ~0.040 ?m in thickness. RF/FS-TEM revealed impressively thick BAEC GCX of ~11 ?m and RFPEC GCX of ~5 ?m. RF/FS-TEM also discerned GCX structure and thickness variations due to heparinase III enzyme treatment and extracellular protein removal, respectively. Immunoconfocal studies confirmed that the in vitro GCX is several microns thick and is comprised of extensive and well integrated heparan sulfate, hyaluronic acid, and protein layers. Conclusions New observations by RF/FS-TEM reveal substantial GCX layers on cultured EC, supporting their continued use for fundamental studies of GCX and its function in the vasculature. PMID:21474821

Ebong, Eno E; Macaluso, Frank P; Spray, David C; Tarbell, John M

2011-01-01

458

Deposition nucleation viewed as homogeneous or immersion freezing in pores and cavities  

NASA Astrophysics Data System (ADS)

Heterogeneous ice nucleation is an important mechanism for the glaciation of mixed phase clouds and may also be relevant for cloud formation and dehydration at the cirrus cloud level. It is thought to proceed through different mechanisms, namely contact, condensation, immersion and deposition nucleation. Supposedly, deposition nucleation is the only pathway which does not involve liquid water but occurs by direct water vapor deposition on a surface. This study challenges this classical view by putting forward the hypothesis that what is called deposition nucleation is in fact homogeneous or immersion nucleation occurring in pores and cavities that may form between aggregated primary particles and fill with water at relative humidity RHw < 100% because of the inverse Kelvin effect. Evidence for this hypothesis of pore condensation and freezing (PCF) originates from a number of only loosely connected scientific areas. The prime example for PCF is ice nucleation in clay minerals and mineral dusts, for which the data base is best. Studies on freezing in confinement carried out on mesoporous silica materials such as SBA-15, SBA-16, MCM-41, zeolites and KIT have shown that homogeneous ice nucleation occurs abruptly at T=230-235 K in pores with diameters (D) of 3.5-4 nm or larger but only gradually at T=210-230 K in pores with D=2.5-3.5 nm. Melting temperatures in pores are depressed by an amount that can be described by the Gibbs-Thomson equation. Water adsorption isotherms of MCM-41 show that pores with D=3.5-4 nm fill with water at RHw = 56-60% in accordance with an inverse Kelvin effect. Water in such pores should freeze homogeneously for T < 235 K even before relative humidity with respect to ice (RHi) reaches ice saturation. Ice crystal growth by water vapor deposition from the gas phase is therefore expected to set in as soon as RHw > 100%. Pores with D > 7.5 nm fill with water at RHi > 100% for T < 235 K and are likely to freeze homogeneously as soon as they are filled with water. Water in pores can freeze in immersion mode at T > 235 K if the pore walls contain an active site. Pore analysis of clay minerals shows that kaolinites exhibit pore structures with pore diameters of 20-50 nm. The mesoporosity of illites and montmorillonites is characterized by pores with T = 2-5 nm. The number and size of pores is distinctly increased in acid treated montmorillonites like K10. Many clay minerals and mineral dusts show a strong increase in ice nucleation efficiency when temperature is decreased below 235 K. Such an increase is difficult to explain when ice nucleation is supposed to occur by a deposition mechanism, but evident when assuming freezing in pores, because for homogeneous ice nucleation only small pore volumes are needed, while heterogeneous ice nucleation requires larger pore structures to contain at least one active site for immersion nucleation. Together, these pieces of evidence strongly suggest that ice nucleation within pores should be the prevailing freezing mechanism of clay minerals for RHw below water saturation. Extending the analysis to other types of ice nuclei shows that freezing in pores and cracks is probably the prevailing ice nucleation mechanism for glassy and volcanic ash aerosols at RHw below water saturation. Freezing of water in carbon nanotubes might be of significance for ice nucleation by soot aerosols. No case could be identified that gives clear evidence of ice nucleation by water vapor deposition on a solid surface. Inspection of ice nuclei with a close lattice match to ice, such as silver iodide or SnomaxTM, show that for high ice nucleation efficiency below water saturation the presence of impurities or cracks on the surface may be essential. Soluble impurities promote the formation of a liquid phase below water saturation in patches on the surface or as a complete surface layer that offers an environment for immersion freezing. If porous aerosol particles come in contact with semivolatile vapors, these will condense preferentially in pores before a coating on

Marcolli, C.

2013-06-01

459

Immersion freezing of biological particles at LACIS  

NASA Astrophysics Data System (ADS)

Biological particles, especially bacteria being ubiquitous in the atmosphere, belong to the most efficient ice nuclei (IN) (Möhler, 2008) and hence might have a large impact on weather and climate. In this study, the immersion freezing behavior of different size segregated biological particles is investigated at the laminar flow tube LACIS (Leipzig Aerosol Cloud Interaction Simulator, Hartmann et al., 2011). For these experiments, SNOMAX and outer membrane vesicles (OMV) are used as IN. SNOMAX industrially produced from Pseudomonas-syringae bacteria, which are very ice nucleation active, can be seen as a proxy for ice nucleating bacteria in general. On the surface of these bacteria, ice nucleating proteins that initiate the freezing are situated (Maki et al., 1974). Additionally, it has been found that some ice nucleating bacteria strains have the ability to produce OMV, i.e., strangulated parts of the bacterial cell consisting of the same membrane material (Phelps et al., 1986). These OMV might contain the same ice nucleating proteins on their surface and thus might be able to nucleate ice as well. The OMV used in our experiments were extracted from bacteria cultivated from rain samples collected in Denmark from 30 m height. In our experiments, the biological particles are suspended in air via atomization, size selected by means of a Differential Mobility Particle Sizer, and then fed into LACIS. In LACIS, well defined droplets are produced by activating the biological particles to cloud droplets, so that each droplet contains only one biological particle. By decreasing the temperature in LACIS, these droplets are frozen. To determine the ice fraction, i.e., the fraction of frozen droplets to all particles, the liquid and frozen droplets are distinguished by means of a newly self-built optical device, which is positioned under LACIS, using the depolarization of light scattered by a single particle. The ice fractions are measured as a function of temperature and then used to determine nucleation rates. For 650 nm and 800 nm SNOMAX particles, the ice fraction versus temperature is a very steep function and almost linear within the temperature range between -3°C and -10°C. The ice fraction observed for the OMV is close to the detection limit, in a range of about 1 %, implying that only a small fraction of the OMV are ice nucleating active. Hartmann, S., et al. (2011), Homogeneous and heterogeneous ice nucleation at LACIS: operating principle and theoretical studies, Atmos. Chem. Phys., 11(4), 1753-1767. Maki, L. R., et al. (1974), Ice nucleation induced by Pseudomonas-syringae, Appl. Microbiol., 28(3), 456-459. Möhler, O., et al. (2008), Heterogeneous ice nucleation activity of bacteria: new laboratory experiments at simulated cloud conditions, Biogeosciences, 5(5), 1425-1435. Phelps, P., et al. (1986), Release of cell-free ice nuclei by erwina-herbicola, J. Bacteriol., 167(2), 496-502.

Clauss, T.; Hartmann, S.; Temkiv, T. S.; Augustin, S.; Gosewinkel Karlson, U.; Sahyoun, M. M.; Niedermeier, D.; Wex, H.; Voigtländer, J.; Raddatz, M.; Stratmann, F.

2012-04-01

460

Inhibition, Executive Function, and Freezing of Gait  

PubMed Central

Background Studies suggest that freezing of gait (FoG) in people with Parkinson’s disease (PD) is associated with declines in executive function (EF). However, EF is multi-faceted, including three dissociable components: inhibiting prepotent responses, switching between task sets, and updating working memory. Objective This study investigated which aspect of EF is most strongly associated with FoG in PD. Method Three groups were studied: adults with PD (with and without FoG) and age-matched, healthy adults. All participants completed a battery of cognitive tasks previously shown to discriminate among the three EF components. Participants also completed a turning-in-place task that was scored for FoG by neurologists blind to subjects’ self-reported FoG. Results Compared to both other groups, participants with FoG showed significant performance deficits in tasks associated with inhibitory control, even after accounting for differences in disease severity, but no significant deficits in task-switching or updating working memory. Surprisingly, the strongest effect was an intermittent tendency of participants with FoG to hesitate, and thus miss the response window, on go trials in the Go-Nogo task. The FoG group also made slower responses in the conflict condition of the Stroop task. Physician-rated FoG scores were correlated both with failures to respond on go trials and with failures to inhibit responses on nogo trials in the Go-Nogo task. Conclusion These results suggest that FoG is associated with a specific inability to appropriately engage and release inhibition, rather than with a general executive deficit. PMID:24496099

Cohen, Rajal G.; Klein, Krystal A.; Nomura, Mariko; Fleming, Michael; Mancini, Martina; Giladi, Nir; Nutt, John G.; Horak, Fay B.

2014-01-01

461

A nonprotein thermal hysteresis-producing xylomannan antifreeze in the freeze-tolerant Alaskan beetle Upis ceramboides.  

PubMed

Thermal hysteresis (TH), a difference between the melting and freezing points of a solution that is indicative of the presence of large-molecular-mass antifreezes (e.g., antifreeze proteins), has been described in animals, plants, bacteria, and fungi. Although all previously described TH-producing biomolecules are proteins, most thermal hysteresis factors (THFs) have not yet been structurally characterized, and none have been characterized from a freeze-tolerant animal. We isolated a highly active THF from the freeze-tolerant beetle, Upis ceramboides, by means of ice affinity. Amino acid chromatographic analysis, polyacrylamide gel electrophoresis, UV-Vis spectrophotometry, and NMR spectroscopy indicated that the THF contained little or no protein, yet it produced 3.7 +/- 0.3 degrees C of TH at 5 mg/ml, comparable to that of the most active insect antifreeze proteins. Compositional and structural analyses indicated that this antifreeze contains a beta-mannopyranosyl-(1-->4) beta-xylopyranose backbone and a fatty acid component, although the lipid may not be covalently linked to the saccharide. Consistent with the proposed structure, treatment with endo-beta-(1-->4)xylanase ablated TH activity. This xylomannan is the first TH-producing antifreeze isolated from a freeze-tolerant animal and the first in a new class of highly active THFs that contain little or no protein. PMID:19934038

Walters, Kent R; Serianni, Anthony S; Sformo, Todd; Barnes, Brian M; Duman, John G

2009-12-01

462

A nonprotein thermal hysteresis-producing xylomannan antifreeze in the freeze-tolerant Alaskan beetle Upis ceramboides  

PubMed Central

Thermal hysteresis (TH), a difference between the melting and freezing points of a solution that is indicative of the presence of large-molecular-mass antifreezes (e.g., antifreeze proteins), has been described in animals, plants, bacteria, and fungi. Although all previously described TH-producing biomolecules are proteins, most thermal hysteresis factors (THFs) have not yet been structurally characterized, and none have been characterized from a freeze-tolerant animal. We isolated a highly active THF from the freeze-tolerant beetle, Upis ceramboides, by means of ice affinity. Amino acid chromatographic analysis, polyacrylamide gel electrophoresis, UV-Vis spectrophotometry, and NMR spectroscopy indicated that the THF contained little or no protein, yet it produced 3.7 ± 0.3 °C of TH at 5 mg/ml, comparable to that of the most active insect antifreeze proteins. Compositional and structural analyses indicated that this antifreeze contains a ?-mannopyranosyl-(1?4) ?-xylopyranose backbone and a fatty acid component, although the lipid may not be covalently linked to the saccharide. Consistent with the proposed structure, treatment with endo-?-(1?4)xylanase ablated TH activity. This xylomannan is the first TH-producing antifreeze isolated from a freeze-tolerant animal and the first in a new class of highly active THFs that contain little or no protein. PMID:19934038

Walters, Kent R.; Serianni, Anthony S.; Sformo, Todd; Barnes, Brian M.; Duman, John G.

2009-01-01

463

Does Platelet-Rich Plasma Freeze-Thawing Influence Growth Factor Release and Their Effects on Chondrocytes and Synoviocytes?  

PubMed Central

PRP cryopreservation remains a controversial point. Our purpose was to investigate the effect of freezing/thawing on PRP molecule release, and its effects on the metabolism of chondrocytes and synoviocytes. PRP was prepared from 10 volunteers, and a half volume underwent one freezing/thawing cycle. IL-1?, HGF, PDGF AB/BB, TGF-?1, and VEGF were assayed 1 hour and 7 days after activation. Culture media of chondrocytes and synoviocytes were supplemented with fresh or frozen PRP, and, at 7 days, proliferation, gene expression, and secreted proteins levels were evaluated. Results showed that in the freeze-thawed PRP the immediate and delayed molecule releases were similar or slightly lower than those in fresh PRP. TGF-?1 and PDGF AB/BB concentrations were significantly reduced after freezing both at 1 hour and at 7 days, whereas HGF concentration was significantly lower in frozen PRP at 7 days. In fresh PRP IL-1? and HGF concentrations underwent a significant further increase after 7 days. Similar gene expression was found in chondrocytes cultured with both PRPs, whereas in synoviocytes HGF gene expression was higher in frozen PRP. PRP cryopreservation is a safe procedure, which sufficiently preserves PRP quality and its ability to induce proliferation and the production of ECM components in chondrocytes and synoviocytes. PMID:25136613

Cavallo, Carola; Cenacchi, Annarita; Facchini, Andrea; Grigolo, Brunella; Kon, Elizaveta; Mariani, Erminia; Pratelli, Loredana; Marcacci, Maurilio

2014-01-01

464

Depression in university students: Duration, relation to calendar time, prevalence, and demographic correlates  

Microsoft Academic Search

The duration, relation to calendar time, prevalence, and demographic correlates of depression in university students were studied by administering the Beck Depression Inventory to 4 independent samples (N?=?222) either once or twice at 3 points in time separated by 3-wk intervals. The 3-wk test–retest reliability was .78. There was no significant effect of the 3 points in time sampled. 17%

J. M. Oliver; Robert Burkham

1979-01-01

465

Freeze resistance in rainbow smelt (Osmerus mordax): seasonal pattern of glycerol and antifreeze protein levels and liver enzyme activity associated with glycerol production.  

PubMed

Rainbow smelt (Osmerus mordax) inhabit inshore waters along the North American Atlantic coast. During the winter, these waters are frequently ice covered and can reach temperatures as low as -1.9 degrees C. To prevent freezing, smelt accumulate high levels of glycerol, which lower the freezing point via colligative means, and antifreeze proteins (AFP). The up-regulation of the antifreeze response (both glycerol and AFP) occurs in early fall, when water temperatures are 5 degrees -6 degrees C. The accumulation of glycerol appears to be the main mechanism of freeze resistance in smelt because it contributes more to the lowering of the body's freezing point than the activity of the AFP (0.5 degrees C vs. 0.25 degrees C for glycerol and AFP, respectively) at a water temperature of -1.5 degrees C. Moreover, AFP in smelt appears to be a safeguard mechanism to prevent freezing when glycerol levels are low. Significant increases in activities of the liver enzymes glycerol 3-phosphate dehydrogenase (GPDH), alanine aminotransferase (AlaAT), and phosphoenolpyruvate carboxykinase (PEPCK) during the initiation of glycerol production and significant correlations between enzyme activities and plasma glycerol levels suggest that these enzymes are closely associated with the synthesis and maintenance of elevated glycerol levels for use as an antifreeze. These findings add further support to the concept that carbon for glycerol is derived from amin