Persistent polycyclic aromatic hydrocarbons removal from sewage sludge-amended soil through phytoremediation combined with solid-state ligninolytic fungal cultures

Polycyclic aromatic hydrocarbons (PAHs) are widely present in the environment, causing increasing concern because of their impact on soil health, food safety and potential health risks. Four bioremediation strategies were examined to assess the dissipation of PAHs in agricultural soil amended with sewage sludge over a period of 120 days: soil-sludge natural attenuation (SS); phytoremediation using maize (Zea mays L.) (PSS); mycoremediation (MR) separately using three white-rot fungi (Pleurotus ostreatus, Phanerochaete chrysosporium and Irpex lacteus); and plant-assisted mycoremediation (PMR) using a combination of maize and fungi. In the time frame of the experiment, mycoremediation using P. chrysosporium (MR-PH) exhibited a significantly higher (P < 0.05) degradation of total PAHs compared to the SS and PSS treatments, achieving a degradation rate of 52 %. Both the SS and PSS treatments demonstrated a lower degradation rate of total PAHs, with removal rates of 18 % and 32 %, respectively. The PMR treatments showed the highest removal rates of total PAHs at the end of the study, with degradation rates of 48-60 %. In the shoots of maize, only low- and medium-molecular-weight PAHs were found in both the PSS and PMR treatments. The calculated translocation and bioconversion factors always showed values < 1. The analysed enzymatic activities were higher in the PMR treatments compared to other treatments, which can be positively related to the higher degradation of PAHs in the soil.

Psychotherapists' Experience with In-Session Use of Routine Outcome Monitoring: A Qualitative Meta-analysis

Routine outcome monitoring (ROM) has become an increasingly utilized tool in therapeutic practice that has the potential to improve therapy outcomes. This study aimed to synthesize the findings of existing qualitative studies investigating how clinicians use ROM in their work with clients. A systematic search of qualitative studies on clinicians' experience with the use of ROM in mental health services was conducted via PsycInfo, PsycArticles, Medline, Web of Science, and Scopus databases. Qualitative meta-analysis was used to synthesize the finding of the primary studies. Forty-seven studies met the inclusion criteria. The analysis resulted in 21 meta-categories organized into six clusters, namely (1) obtaining clinically relevant information, (2) adapting treatment, (3) facilitating communication, (4) enhancing the therapeutic relationship, (5) facilitating change in clients, and (6) personalized usage of ROM. The meta-analysis revealed that clinicians utilized ROM in diverse ways, including both informational and communicational functions. From the clinicians' perspective, ROM was an element that, on the one hand, introduced additional structure and standardization in treatment and, on the other hand, allowed for greater flexibility and tailoring of treatment.

Formation of Domains within a Lower-to-Higher Symmetry Structural Transition in CrI3

CrI3 represents one of the most important van der Waals systems on the route to understanding 2D magnetic phenomena. Being arranged in a specific layered structure, it also provides a unique opportunity to investigate structural transformations in dimension-confined systems. CrI3 is dimorphic and possesses a higher symmetry low-temperature phase, which is quite uncommon. It contrasts with vanadium trihalides, which show a higher symmetry high-temperature phase. An explanation of this distinct behavior, together with a large cycle-dependent transition hysteresis, is still an open question. Our low-temperature X-ray diffraction study conducted on CrI3 single crystals complemented by magnetization and specific heat measurements was focused mainly on specific features of the structural transition during cooling. Our results manifest that the structural transition during cooling relates to the formation of structural domains despite the lower symmetry structure transforming to a higher symmetry one. We propose that these domains could control the size of thermal hysteresis.

Investigation of genetic diversity and polyandry of Leptinotarsa decemlineata using X-linked microsatellite markers

A panel of X-linked microsatellite markers was newly designed using the data from a previous sequencing project available in NCBI and used for a study of the Colorado potato beetle (CPB, Leptinotarsa decemlineata) X-haplotype variability. The analysis of scaffolds 49 and 61 (newly identified as fragments of CPB chromosome X) found ten high-quality markers, which were arranged in two PCR multiplexes and evaluated in both 420 CPB adults, collected from 14 localities of Czechia and Slovakia, and 866 larvae from five single-female families from two more Czech localities. Length polymorphisms found in 6 loci have predicted 192 potential X-haplotypes, however, only 36 combinations were detected in the adult males (N = 189), and seven additional ones in the larvae. The X-haplotypes were also generally unevenly distributed; five of the most frequent haplotypes were detected in 55% of males, 19 repeating up to ten-times in 38.7% of males and the remained 12 occurred uniquely in 6.3% of males. Bulk analysis of X-haplotypes dissimilarity indicated seven haplotype groups diversified by mutations and recombinations. Two haplotypes showed a distinctive regional distribution, which indicates an east-west disruption of CPB migration probably caused by different environments of localities in the South Bohemia region and Vysocina region. On the contrary, the results indicate a south-north migration corridor alongside the Vltava River. In the single-female families, from 6 to 13 distinct paternal haplotypes were detected, which proved and quantified a frequented polyandry in CPB.

Bioremediation of the synthetic musk compounds Galaxolide and Tonalide by white rot fungal strain-assisted phytoremediation in biosolid-amended soil

The study was aimed to conduct the bioremediation of synthetic musks by four species of white rot fungi combined with phytoremediation (Zea mays) in biosolid-amended soils where only Galaxolide (HHCB) and Tonalide (AHTN) were found as other musks were below the detection limit (0.5-2 μg/kg dw). The HHCB and AHTN concentration in natural attenuation treated soil was decreased by not more than 9%. In solely mycoremediation, Pleurotus ostreatus was found to be the most efficient fungal strain, with the higher (P < 0.05) HHCB and AHTN removal (51.3% and 46.4%). Phytoremediation-only of biosolid-amended soil was also able to remove HHCB and AHTN from soil significantly (P < 0.05) in comparison to the control treatment without plants which resulted in the final concentration for both compounds of 56.2 and 15.3 μg/kg dw, respectively. Using white rot fungus-assisted phytoremediation, only P. ostreatus decreased the HHCB content in soil significantly (P < 0.05) by 44.7%, when compared to the initial concentration. While using Phanerochaete chrysosporium, the AHTN concentration was decreased by 34.5%, which was a significantly lower concentration at the end of experiment compared to the initial value. Via fungus-assisted phytoremediation, the enzymatic activity and fungal biomass were increased, probably due to the presence of roots in association with the soil microbiome, in the process increasing the degradation of fragrances accordingly. This could lead to a higher (P < 0.05) AHTN removal in P. chrysosporium assisted phytoremediation. Estimated HHCB and AHTN bioaccumulation factors in maize were lower than 1, therefore no environmental risk would be posed.

Accumulation of Toxic Arsenic by Cherry Radish Tuber (Raphanus sativus var. sativus Pers.) and Its Physiological, Metabolic and Anatomical Stress Responses

In a pot experiment, cherry radish (Raphanus sativus var. sativus Pers. 'Viola') was cultivated under two levels of As soil contamination-20 and 100 mg/kg. The increasing As content in tubers with increasing soil contamination led to changes in free amino acids (AAs) and phytohormone metabolism and antioxidative metabolites. Changes were mainly observed under conditions of high As contamination (As100). The content of indole-3-acetic acid in tubers varied under different levels of As stress, but As100 contamination led to an increase in its bacterial precursor indole-3-acetamide. A decrease in cis-zeatin-9-riboside-5'-monophosphate content and an increase in jasmonic acid content were found in this treatment. The free AA content in tubers was also reduced. The main free AAs were determined to be transport AAs (glutamate-Glu, aspartate, glutamine-Gln, asparagine) with the main portion being Gln. The Glu/Gln ratio-a significant indicator of primary N assimilation in plants-decreased under the As100 treatment condition. A decrease in antioxidative metabolite content-namely that of ascorbic acid and anthocyanins-was observed in this experiment. A decline in anthocyanin content is related to a decrease in aromatic AA content which is crucial for secondary metabolite production. The changes in tubers caused by As contamination were reflected in anatomical changes in the radish tubers and roots.

Pheromone Dispenser Acumiprotect for Mass Trapping of the Sharp-Dentated Bark Beetle, Ips acuminatus (Coleoptera; Curculionidae)

The sharp-dentated bark beetle (Ips acuminatus Glyl.) is one of the most aggressive European bark beetle species with the occurrence in pine. This communication discusses the experience with a new pheromone dispenser Acumiprotect from a practical point of view. Full text English translation is available in the on-line version. Kůrovec vrcholkový (Ips acuminatus Glyl.) je jedním z nejagresivnějších evropských druhů kůrovců s výskytem na borovici. Toto sdělení pojednává o zkušenostech s novým feromonovým dávkovačem Acumiprotect z praktického hlediska.

Effects of genotype, sex, and feed restriction on the biochemical composition of chicken preen gland secretions and their implications for commercial poultry production

Preen gland secretions spread on the feathers contain various chemical compounds dominated by fatty acids (FAs) and volatile organic compounds (VOCs). These chemicals may significantly affect plumage condition, microbial and ectoparasitic load on feathers, and chemical communication of birds. However, how chemical composition of preen secretions varies in commercially produced chickens with respect to their genotype, sex, and feeding regime remain largely unknown, as well as the welfare implications for farmed poultry. We found that while polyunsaturated fatty acids in chicken preen secretions differed significantly with genotype (P << 0.001), saturated fatty acids and monounsaturated fatty acids varied with genotype-dependent preen gland volume (P < 0.01). Chickens of meat-type fast-growing Ross 308 genotype had reduced preen gland volume and lower proportions of all FA categories in their preen secretions compared with dual-purpose slow-growing ISA Dual chickens. A total of 34 FAs and 77 VOCs with tens of unique FAs were detected in preen secretions of both genotypes. While differences in the relative proportion of 6 of the 10 most dominant VOCs in chicken preen gland secretions were related to genotype (P < 0.001), only 1 of the 10 most dominant VOCs showed a sex effect (P < 0.01), and only 2 of the 10 most dominant VOCs showed a genotype-dependent effect of feed restriction (P < 0.05). Feed restriction had no effect on the relative proportion of any of the FAs in chicken preen gland secretions. Moreover, we found that meat-type Ross 308 preen secretions were dominated by VOCs, which are proven attractants for poultry red mite and may also increase infestation with other ectoparasites and negatively influence overall odor-mediated intraspecific communication and welfare. This study shows that no feeding management, but long-term genetic selection in commercial breeding may be the main cause of the differences in the biochemistry and function of chicken preen secretions. This might have negative consequences for chemosignaling, antiparasitic, and antimicrobial potential of preen secretions and can lead to increased susceptibility to ectoparasites, plumage care disorders, and can affect the overall condition, welfare, and productivity of commercially bred chickens. Selection-induced preen gland impairments must therefore be considered and compensated by proper management of the chicken farm and increased care about animal well-being.

Terahertz Magnetic and Lattice Excitations in van der Waals Ferromagnet VI3

We use the synergy of infrared, terahertz, and Raman spectroscopies with DFT calculations to shed light on the magnetic and lattice properties of VI₃. The structural transition at T_S1 = 79 K is accompanied by a large splitting of polar phonon modes. Below T_S1, strong ferromagnetic fluctuations are observed. The variations of phonon frequencies at 55 K induced by magnetoelastic coupling enhanced by spin-orbit interaction indicate the proximity of long-range ferromagnetic order. Below T_C = 50 K, two Raman modes simultaneously appear and show dramatic softening in the narrow interval around the temperature T_S2 of the second structural transition associated with the order-order magnetic phase transition. Below T_S2, a magnon in the THz range appears in Raman spectra. The THz magnon observed in VI₃ indicates the application potential of 2D van der Waals ferromagnets in ultrafast THz spintronics, which has previously been considered the exclusive domain of antiferromagnets.

Crystal structure evolution in the van der Waals vanadium trihalides

Most transition-metal trihalides are dimorphic. The representative chromium-based triad, CrCl₃, CrBr₃, CrI₃, is characterized by the low-temperature (LT) phase adopting the trigonal BiI₃-type while the structure of the high-temperature (HT) phase is monoclinic of AlCl₃type (C2/m). The structural transition between the two crystallographic phases is of the first-order type with large thermal hysteresis in CrCl₃and CrI₃. We studied crystal structures and structural phase transitions of vanadium-based counterparts VCl₃, VBr₃, and VI₃by measuring specific heat, magnetization, and x-ray diffraction as functions of temperature and observed an inverse situation. In these cases, the HT phase has a higher symmetry while the LT structure reveals a lower symmetry. The structural phase transition between them shows no measurable hysteresis in contrast to CrX₃. Possible relations of the evolution of the ratioc/aof the unit cell parameters, types of crystal structures, and nature of the structural transitions in V and Cr trihalides are discussed.

La2Pd2In: superconductivity and lattice properties at ambient and elevated pressures

Lattice and electronic properties of La₂Pd₂In were studied at ambient and elevated pressures so as to determine features related to a specific atomic coordination without any influence of magnetism. We describe temperature dependences of lattice parameters, heat capacity and electrical resistivity of single-crystalline La₂Pd₂In (s.g.P4/mbm) in a broad temperature range 0.09-300 K. Together with the anisotropic effect of hydrostatic pressure, showing that the lattice is more compressible in the basal plane, we can conclude that the lattice is affected by degrees of freedom of the La atoms with positions not imposed by symmetry. The lattice anisotropy is smaller than that found for isostructural ferromagnet Ce₂Pd₂In. The equilibrium bulk modulusB₀= (48 ± 3) GPa was determined on the basis of individual linear compressibilities. Measurement of electrical resistivity indicated a superconducting state belowT= 0.59 K with a low critical field 0.005 T atT= 380 mK. The onset of superconducting state as a bulk property of La₂Pd₂In was confirmed by measurements of specific heat and AC magnetic susceptibility. Experimental data can be accounted by first-principles electronic-structure calculations based on density-functional theory. The measured Sommerfeld coefficientγ= 10.6 mJ mol^-1 K^-2, only marginally exceeding the calculatedγ= 9.34 mJ mol^-1 K^-2, indicates only weak electronic correlations.

Adult Feeding Preference and Fecundity in the Large Pine Weevil, Hylobius abietis (Coleoptera: Curculionidae)

Adult feeding preferences of Hylobius abietis on Picea abies, Larix decidua, Pinus sylvestris, Pseudotsuga menziesii, Abies alba and Betula pendula were tested in outdoor conditions. The preferred food source was P. menziesii, and the mean bark area consumed per seedling was 440.8 ± 147.9 mm2. The second most preferred host was P. abies. The coniferous species that suffered the least damage was A. alba (76.8 ± 62.56 mm2 per seedling). B. pendula was the least preferred source of food, and it caused mortality of 60% of weevils that fed on it. Weevils exhibited large differences in fecundity when fed with different tree species in a laboratory experiment. The largest number of eggs was laid by females fed with P. abies. Mean egg numbers reached 26.4 ± 24.89 eggs per experiment for P. abies. Similar fecundity was observed in weevils fed with twigs of P. sylvestris. Oviposition was approximately six times lower in females fed with L. decidua and P. menziesii. The maximum number of eggs laid by a single female during a one-month experiment was 90. The results are discussed in relation to management of H. abietis.

CePt2Al2: Structural and Bulk Properties

This work is focused on the structural and physical properties of CePt₂Al₂, an intermetallic compound. At room temperature, the modulated orthorhombic structure Cmme(a00)000, with q→= (0.481, 0, 0) has been determined by single-crystal X-ray diffraction supplemented by dependence of lattice parameters above room temperature for which the X-ray powder diffraction was used. The compound undergoes a structural transition to a tetragonal structure above room temperature. This transition exhibits 50 °C hysteresis and creates a domain structure in the sample. The magnetic behavior has been studied by specific heat, magnetization, and transport measurements in the temperature range between 0.5 and 300 K. Specific heat and susceptibility shows an antiferromagnetic order below 2 K. On the basis of electrical resistivity and other bulk measurements, CePt₂Al₂ can be considered a Kondo lattice material. The presence of a modulated crystal structure opens the possibility of a charge density wave state in CePt₂Al₂ as observed for (Re)Pt₂Si₂.

Optimised method for determination hypoglycine A in maple plant material by multidimensional gas chromatography/mass spectrometry

In 2018, more than 50 cases of horse death by equine atypical myopathy (AM) were reported in the Czech Republic. This disease is often associated with the toxin hypoglycine A (HGA), which is found in several maple plant materials. To monitor this toxin in products of these trees that grow in or around horse pastures, a rapid and inexpensive analytical method that can provide the required accuracy is needed. Until now, maple samples have been prepared for gas chromatography using time-consuming methods, with preparation processes taking longer than 1 h. In this work, a shorter method (25 min) with an accuracy of 90-94 %, reproducibility of 2-5%, precision of 3-9%, and linearity, with an R² of 0.999, is presented. This sample preparation consists of a procedure without an SPE extraction step and consumes a lower volume of solvent during the extraction. The limit of quantitation for HGA in plant material was improved from 0.5 μg/g of plant material in previous studies to 0.2 μg/g. The method was validated according to the guideline CD 2002/657/EC and ISO 17025, and was found to have good performance characteristics. This simple and rapid method was tested for the monitoring of hypoglycine A level in maple sycamore plant material (seeds, seedlings, and leaves) during the entire growth of the trees.

Ab initio calculations of the crystal field and phonon dispersions in CePd2Al2 and LaPd2Al2

CePd₂Al₂ crystallizes in the CaBe₂Ge₂-type tetragonal structure (P4/nmm, 129) and undergoes a phase transition to the orthorhombic Cmme structure at around 13 K. Its inelastic neutron spectra reveal an additional magnetic excitation that was ascribed to electron-phonon interaction leading to a formation of a new quantum quasi-bound vibron state. We present the first-principles calculations of the crystal field excitations and lattice dynamics calculations of the phonon dispersions to compare with the experimental data. The calculated crystal field energy splitting in CePd₂Al₂ agrees well with the model used to describe the experimental neutron scattering spectra. The first excited crystal field level moves to higher energies when undergoing the transformation from tetragonal to orthorhombic structure, in agreement with the experiment. The analysis based on calculated elastic constants and lattice dynamics calculations show that in both tetragonal and orthorhombic structures there are no imaginary modes for any q-wave vector within the Brillouin zone, and therefore the lattice structures are stable. The phonon dispersions and density of states are calculated for both crystal structures of CePd₂Al₂ and its nonmagnetic counterpart LaPd₂Al₂. The results generally agree well with the experimental data including the high phonon density of states around 12 meV. The phonon density of states is also used to calculate the mean squared displacement, Debye temperature, lattice heat capacity and compared with similar properties of the available experiment.

Local atomic arrangement in LaCuAl3 and LaAuAl3 by NMR and density functional theory

CeCuAl₃ and CeAuAl₃, crystallizing in the non-centrosymmetric BaNiSn₃ tetragonal structure, are known mainly for their unusual neutron scattering spectra involving additional excitations ascribed to vibron quasi-bound quantum state in CeCuAl₃ and anti-crossing of phonon and crystal field excitations in CeAuAl₃. In this work, we present results of nuclear magnetic resonance (NMR) experiments on their lanthanum analogues-[Formula: see text] and [Formula: see text]. The character of NMR spectra of [Formula: see text], [Formula: see text], and ⁶⁵Cu measured in [Formula: see text] and [Formula: see text] is dominated by electric quadrupole interaction. The spectral parameters acquired from experimental data are confronted with values obtained from the electronic structure calculations. The results show remarkable differences for the two compounds. The [Formula: see text] spectrum in [Formula: see text] can be interpreted by a single spectral component corresponding to uniform environment of La atoms in the crystal structure, whereas for [Formula: see text] the spectrum decomposition yields a wide distribution of spectral parameters, which is not possible to explain by a single La environment, and multiple non-equivalent La positions in the crystal structure are required to interpret the spectrum.

Why did she leave? Development of working alliance in a case of psychotherapy for depression

The present case study aims to explore the unfolding of the working alliance in a case that ended with the client dropping out of psychotherapy, unilaterally cutting off her contact with the therapist. However, both quantitative and qualitative outcome assessments strongly suggested that. An analysis of session transcripts, the Client Change Interview, and the Interpersonal Process Recall interviews for three selected sessions was used to analyze the development of the working alliance and its contribution to the dropout. This case study illustrates how the working alliance is constructed differently during the different phases of the therapeutic process. Specifically, the fruitful problem-solving in the first part of psychotherapy helped the client to improve her functioning. Yet this intervention seemed to exhaust its potential over time, and later the dyad had trouble finding another useful mode of interaction due to the interpersonal context, leading to more serious ruptures and, eventually, to the dropout. The findings are discussed in terms of therapist responsiveness and of its role in the continuous negotiation of the working alliance.

The effect of feeding wheat varieties with different grain pigmentation on growth performance, texture, colour and meat sensory traits of broiler chickens

The feeding effect of of three spring wheat genotypes (Vánek, Konini and UC66049) with different grain colour on growth performance, body composition and meat quality parameters of broiler chickens was tested. Ninety chickens were divided into three groups (control, Konini and UC) with 30 chickens in each. The tested genotypes were compares with standard variety Vánek (control) with common (red) grain colour. The two experimental groups received feed mixtures containing 38.2% of wheats with different grain colour: groups Konini (n = 30) and UC (n = 30) with. The third group (n = 30) had 38.2% of common wheat Vánek cultivar (Control group). The live weight of chickens between the experimental groups and control group was not significant different, as well as body composition and chemical analysis of breast and thigh meat of chickens. The feeding of wheat with different grain colour had no effect on performance parameters of broiler chickens. Breast meat tenderness according to the Razor Blade Shear Force was higher in control group against experimental groups. The colour change was not significantly different in all coordinates. pH values (measured after 1-hour post mortem) were found significantly higher in the group fattening with Konini wheat than control and UC groups. Chickens meat from the experimental group was characterised by steady overall quality. The effect of various feeding had no effect on meat quality in terms of relevance to consumers.

The effect of feeding milk thistle seed cakes on quality indicators of broiler chickens meat

This study was conducted to evaluate the effect of feeding milk thistle (Silybum marianum L.) seed cakes at dose 5% and 15% in feed mixture on quality indicators of broiler chickens meat. The used milk thistle seed cakes contained 3.73% of flavonolignans and 129.83 mg.kg-1 of cyanidin-3-glucoside. A 150 cockerels of Ross 308 were divided into three equal groups. The chickens were fattened on conventional deep litter system. The experimental groups received feed mixtures containing 5% of milk thistle seed cakes (MT5), 15% of milk thistle seed cakes (MT15) and third group was control - without milk thistle seed cakes (C). The trial lasted 37 days. At the end of trial was observed significant higher average weight of chickens (2,320.31 g) in control group. Compare to that the experimental group MT5 achieved significant lower mean bodyweight 2,166.69 g. From the perspective of fattening was decreased growth of chickens where a higher percentage of milk thistle seed cakes (MT15). The group MT15 was up to 420 g lower slaughter weight compared to the control group. This was probably due to the higher content of fiber in the feed. At the end of experiment 15 birds were selected randomly from each group, weighed and slaughtered. Feathers were removed and chickens were eviscerated. Carcass yield was calculated for each group like as percentage of live weight. The MT5 and MT15 group had significantly higher breast meat tenderness that the control group. Initial pH1 was highest in group with its middle addition of milk thistle seed cakes (MT5). Significant differences were not observed between control and group MT15. Breast meat was rated as the best in parameter flavour in control and MT15 group. The thigh meat was evaluated significantly best for colour parameter in MT15 group. Fibreness was rated as the finest in MT15 group. The addition of milk thistle seed cakes do not worsened sensory characteristic of breast or thigh meat of broilers and reflects optimal sensory quality traits.

Physiology of cold tolerance in the bark beetle, Pityogenes chalcographus and its overwintering in spruce stands

The seasonal development of physiological features underlying gradual acquisition of relatively high cold tolerance in overwintering adults of the bark beetles, Pityogenes chalcographus was described. Prior to overwintering, the beetles accumulated carbohydrate reserves in the form of glycogen and trehalose. These reserves were partially converted to glycerol during peaking winter so that glycerol concentration reached 1.4M in average, which corresponds to approximately one quarter of the beetle dry mass. Whole body supercooling points decreased from -12.8°C in average at the beginning of dormancy (August) to -26.3°C in average during peaking winter (January). More than 75% of January-collected beetles survived at -5°C for 30days, at -15°C for 60days and more than 40% of them survived at -26°C for 12h. High resistance against inoculation of body fluids with external ice crystals, and low mortality, was observed when January-collected beetles were encased in an ice block for 14days. Thus, the physiological limits of cold tolerance measured at individual level in laboratory were safely sufficient for survival of P. chalcographus at any conceivable cold spell that may occur in Central Europe. In contrast, the field experiment showed that winter survival fluctuated between 23.8% and 69.2% at a population level depending on microclimatic conditions in different altitudes and overwintering locations (standing tree trunk or ground level). The meaning of laboratory-assessed physiological limits of cold tolerance for predictions of population winter survival in the field is discussed.