Nitrate (NO3 (-) ) export coupled with high inorganic nitrogen (N) concentrations in Alaskan streams suggests that N cycles of permafrost-influenced ecosystems are more open than expected for N-limited ecosystems. We tested the hypothesis that soil thaw depth governs inorganic N retention and removal in soils due to vertical patterns in the dominant N transformation pathways. Using an in situ, ...

STUDY QUESTION What are the clinical efficacy and perinatal outcomes following transfer of vitrified blastocysts compared with transfer of fresh or of slow frozen blastocysts? SUMMARY ANSWER Compared with slow frozen blastocysts, vitrified blastocysts resulted in significantly higher clinical pregnancy and live delivery rates with similar perinatal outcomes at population level. WHAT IS KNOW...

OBJECTIVE To analyze cases in which no sperm could be identified after thawing among cryopreserved samples of rare or very low concentrations of sperm. DESIGN Retrospective, single-institution, cross-sectional. SETTING Male infertility clinic. PATIENT(S) We identified couples that underwent intracytoplasmic sperm injection (ICSI) with the use of either ejaculated or testicular cryopreserv...

Measurement of fecal cytokines has been used as a marker of intestinal inflammation in people and correlates with endoscopic findings. The aim of this study was to evaluate the use of canine-specific enzyme-linked immunosorbant assays (ELISAs) for quantification of cytokines in canine fecal samples as a non-invasive biomarker. Interleukin (IL)-6, -8, -10, -23/12p40 and TNF- were assessed by us...

Microbial activity is known to continue during the winter months in cold alpine and Arctic soils often resulting in high microbial biomass. Complex soil nutrient dynamics characterize the transition when soil temperatures approach and exceed 0 1C in spring. At the time of this transition in alphine soils microbial biomass declines dramatically together with soil pools of available nutrients. Th...

Variations in environmental conditions have been recognized by pavements engineers as a major factor affecting pavement performance. These variations resulting from freeze-thaw (F-T) or wet-dry (W-D) actions can significantly affect the engineering properties of pavement material. In this study, the effect of W-D and F-T cycles, on the resilient modulus (Mr) of stabilized aggregate bases is exa...

Freeze–thaw cycles under the conditions of snowmelt and rainfall infiltration in winter are triggers for petroglyph weathering. Rock samples from Helan Mountains were subjected freeze–thaw various laboratory testing, mass, elastic wave velocity unconfined compressive strength tested. The results show that mass loss rate, decreased. In addition, according to XRD analyses, content calcite feldspa...

The mechanical deterioration of soft rocks under freeze–thaw cycles is caused by the accumulation mesoscopic damage. However, current model for does not adequately consider multiscale correlations, which makes strength calculation results differ greatly from test and cannot fully reveal damage mechanism cycling conditions. In this paper, bond pore ice expansion laws are considered soft-rock uni...

Freezing and thawing of soils may affect the turnover of soil organic matter and thus the losses of C and N from soils. Here we review the literature with special focus on: (i) the mechanisms involved, (ii) the effects of freezing temperature and frequency, (iii) the differences between arable soils and soils under natural vegetation, and (iv) the hypothesis that freeze-thaw events lead to sign...

It is not well understood what determines the degree of supercooling of apoplastic sap in trees, although it determines the number and duration of annual freeze-thaw cycles in a given environment. We studied the linkage between apoplastic ice nucleation temperature, tree water status, and conduit size. We used branches of 10 gymnosperms and 16 angiosperms collected from an arboretum in Helsinki...