Length Of Phase Research Articles

Time length of adaptation phase for subjective thermal environment evaluation based on thermal stability time

The adaptation phase is the primary process of subjective thermal comfort evaluations. The time length of the adaptation phase in existing studies disperses largely, which either risks low evaluation reliability or high time and economic costs. This study proposes to determine the time length of the adaptation phase for reliable subjective thermal environment evaluation and to avoid unnecessarily large time and economic costs. First, the variation and distribution of the initial thermal status of the adaptation phase are inferred from a steady bioheat model with ASHRAE (American Society of Heating, Refrigerating and Air-conditioning Engineers) Thermal Comfort Database II. Second, with the initial thermal status, the variation and distribution of the thermal stability time are inferred from the dynamic bioheat model. Third, the time length of the adaptation phase is quantified from the distribution of the thermal stability time according to the targeted reliability level. Results show that under the summer scenario, the time length of the adaptation phase increases from 16.9 – 31.2 min to 25.2 – 38.9 min when the reliability level increases from 90.0 % to 97.5 %. The time length of the adaptation phase of the winter scenario increases by 5.3 – 9.7 min relative to that of the summer scenario. A strategy of shifting the adaptation phase from thermal neutrality to slight warmth is proposed to effectively shorten the time length of the adaptation phase by 5.6 % – 19.4 % and 7.8 % – 23.9 % in the summer and winter scenarios respectively. These results are tabulated for practical convenience.

Effect of temperature on creep aging behavior of the nugget zone of AA2195 Al[sbnd]Li alloy produced by friction stir welding

This paper aims to study the effect of temperatures on the creep aging behaviors of the nugget zone (NZ) of AlLi alloy by friction stir welding (FSW). The results suggest that the creep strain of the NZ experiences a significant increase as the temperature rises, surpassing that of the base material (BM) at equivalent temperatures. In the case of NZ, the elevation of temperature from 160 to 190 °C induces a pronounced increase in both the size and volume fraction of the T1 phase, which results in a substantial enhancement in the strength. In contrast, the peak-aged strengths of the BM exhibit minimal variation in this temperature range. As the temperature increases, the time required for the BM to reach its peak aging state significantly decreases, whereas the changes in the NZ are less pronounced. For the NZ, the time required to reach the peak aging state is obviously longer than that for the BM. Although the average length of the T1 phase in the NZ is markedly greater than that in the BM, its volume fraction and number density in the NZ are considerably lower than those in the BM, resulting in inferior strength reinforcement in the NZ compared to the BM after creep aging.

Impinging ceiling flame behaviors induced by wall-attached gaseous fuel fires at one end in a narrow building corridor: Different phases and generalized correlations

This work investigated the flame extension behavior after impinging upon a ceiling induced by wall-attached fires at the closed end in a narrow building corridor. Experiments were conducted in a reduced scale corridor with one end closed and the other opened, under various fire heat release rates and source-ceiling heights (from 0.05 m to 0.50 m) of totally 353 test conditions. The flame morphological characteristic parameters involving the flame extension length in the center of the ceiling and in the two sides were measured and analyzed comprehensively. By a careful observation, it was found that, as the fire heat release rate increased or the source-ceiling height decreased, the ceiling flame extension behavior can be divided into different behavior phases: the flame spreads to the two sides after impinging the narrow building ceiling; flame extends longitudinally after reaching side walls, presenting a semi-elliptical shape; flame in the two sides extends farther than that in the center of the ceiling, presenting a “U” shape; and flame presents a cellular structure (the fire source is near the building ceiling). The dimensionless critical fire heat release rates for the transition of these phases were identified, and non-dimensional correlations were obtained for the prediction of flame extension lengths of different phases. This work provides new observations of different phases and generalized correlations for impinging ceiling flame behaviors induced by wall-attached gaseous fuel fires at one end in a corridor.

Metacommunity structures of dormant and active zooplankton in two distant mediterranean regions

Abstract Temporary ponds are small‐sized limnic systems that dry periodically. The length of the wet phase defines the hydroregime and determines community assembly in temporary ponds. Zooplankton species have adapted to desiccation by adopting some dormant strategies, such as the formation of resting stages. Hatching from resting stages is a source of recolonization after drought events and the composition of hatching taxa is also influenced by hydroregime. We compared metacommunity structure and composition of the dormant sub‐community (resting stages); the pioneer active sub‐community (fauna present immediately after inundation of ponds); and the cumulative active sub‐community (fauna present at the initial, middle and final phases of hydroperiod) in a set of temporary ponds with semipermanent and seasonal hydroregimes in two areas with mediterranean climate: central Chile and eastern Spain. We aimed to determine the influence of hydroregime and identify whether metacommunity patterns are consistent between regions sharing a mediterranean climate. We selected five semipermanent and five seasonal ponds in each region to sample sediments and active zooplankton sub‐communities. By combining hatching experiments from the sediments with direct counts of active zooplankton from the field samples, we gathered data on both dormant and active sub‐communities to build unweighted bipartite networks of species occurrences in each pond. The obtained networks were analysed to determine seasonal trends in structural features of the metacommunities (diversity, nestedness and modularity) and their relation to hydroregime (semipermanent and seasonal) and geographical location (Chile and Spain). We observed consistent differences in community structure when comparing sub‐communities at different successional stages (dormant, pioneer active and cumulative active) and with different hydroregimes (semipermanent vs. seasonal). Both α‐ and γ‐diversity showed a consistent trend, being highest in cumulative active sub‐communities and lowest in dormant ones, and were consistently higher in seasonal ponds, regardless of the region. In addition, β‐diversity was higher in the pioneer active sub‐community in both regions, with no significant differences between hydroregimes. The species composition of cumulative active sub‐communities were less heterogeneous than that of the pioneer and dormant ones. No consistent patterns were found in modularity and nestedness values across sub‐communities and hydroregimes. In agreement with our hypotheses, we observed a gradual accumulation of taxa as well as community homogenization over time in both regions. Contrary to our expectations, hydroregime did not affect these patterns and, surprisingly, shorter hydroperiods exhibited higher regional diversity. Our results suggest that hydroregime as a single variable does not have a strong explanatory power for metacommunity assembly of temporary ponds. Therefore, a more comprehensive theory is needed to anticipate the effects of the upcoming hydroperiod shortening.

Approaching 20% Efficiency in Ortho-Xylene Processed Organic Solar Cells by a Benzo[a]phenazine-Core-Based 3D Network Acceptor with Large Electronic Coupling and Long Exciton Diffusion Length.

High-performance organic solar cells often rely on halogen-containing solvents, which restrict the photovoltaic industry. Therefore, it is imperative to develop efficient organic photovoltaic materials compatible with halogen-free solvents. Herein, a series of benzo[a]phenazine (BP)-core-based small-molecule acceptors (SMAs) achieved through an isomerization chlorination strategy is presented, comprising unchlorinated NA1, 10-chlorine substituted NA2, 8-chlorine substituted NA3, and 7-chlorine substituted NA4. Theoretical simulations highlight NA3's superior orbit overlap length and tight molecular packing, attributed to interactions between the end group and BP unit. Furthermore, NA3 demonstrates dense 3D network structures and a record electronic coupling of 104.5 meV. These characteristics empower the ortho-xylene (o-XY) processed PM6:NA3 device with superior power conversion efficiency (PCE) of 18.94%, surpassing PM6:NA1 (15.34%), PM6:NA2 (7.18%), and PM6:NA4 (16.02%). Notably, the significantly lower PCE in the PM6:NA2 device is attributed to excessive self-aggregation characteristics of NA2 in o-XY. Importantly, the incorporation of D18-Cl into the PM6:NA3 binary blend enhances crystallographic ordering and increases the exciton diffusion length of the donor phase, resulting in a ternary device efficiency of 19.75% (certified as 19.39%). These findings underscore the significance of incorporating new electron-deficient units in the design of efficient SMAs tailored for environmentally benign solvent processing of OSCs.

DYNAMIC VIRAL LOAD MONITORING AND METAGENOMIC SEQUENCING IN ACUTE RETINAL NECROSIS CAUSED BY VARICELLA-ZOSTER VIRUS.

To analyze the trend of intraocular viral load after antiviral treatment in patients with varicella-zoster virus-induced acute retinal necrosis and to explore the effect of viral genotypes on clinical manifestations. In this case series, viral load was detected using polymerase chain reaction from aqueous humor during treatment; viral load curves were fitted, and the time required to reach the inflection point between plateau phase and logarithmic reduction phase was estimated. Variations in viral genomes were detected by metagenomic sequencing. Twenty eyes of 20 patients were included. The median (interquartile range) initial viral load was 5.9 × 10 7 (1.1 × 10 7 -1.1 × 10 8 ) copies/mL. The average duration of retinitis was 5 ± 3 weeks. The average time required to reach the inflection point was 4.2 ± 1.6 days. Time required to reach the inflection point was correlated with the duration of retinitis ( P = 0.025). Patients with varicella-zoster virus carrying the p.S715* variation in ribonucleotide reductase ( RNR ) subunit 1 gene had lower initial viral loads (median 1.3 × 10 7 copies/mL) than those without (median 1.1 × 10 8 copies/mL; adjusted P = 0.030). The inflection of viral load curve is helpful to estimate the length of plateau phase and the duration of retinitis during antiviral treatment in patients with acute retinal necrosis. Loss-of-function variation in RNR gene might be correlated with lower virulence of varicella-zoster virus.

Effect of 60 °C sustained temperature conditions on the mechanical properties and microstructure of alkali-activated fly ash-slag pastes and mortars

The temperature effect has been proven to affect the mechanical properties and microstructure of alkali-activated materials greatly. The research on the long-term complex high-temperature environment for alkali-activated materials remains blank. In this paper, the actual working temperature is selected to study the effects of long-term exposure at 60 °C on the mechanical properties of static/impact load, quality, shrinkage deformation, hydration products, pore structure, and microscopic morphology of alkali-activated fly ash-slag (AAFS). The results show that the mass loss rate of AAFS tends to be stable, the shrinkage deformation rate decreases, and the compressive strength decreases after 28d of sustained high-temperature action. The sustained high temperature causes changes in the hydration product phase, mean chain length (MCL) of the gel phase, pore structure, and micro-morphology. When the duration for 7d and 28d at 60 °C temperature, the compressive strength under static and impact loads increases, which is related to the increase of diffraction peak and MCL of the gel phase; when the duration is 60d and 90d, the compressive strength under static/impact loads decreases, which is related to the increase of cumulative pore volume and the decrease of MCL. Sustained high temperature refines the pore diameter of AAFS samples.

Regulation of the size and flow pattern of yield stress droplets in flow-focused microchannels by orifice constraints

Although droplet microfluidics have attracted increasing research interest, the regulation of complex polymeric droplets remains incomplete in chemical industry. In this study, we investigate the formation of yield stress droplets in flow-focused microchannels with orifice constraints by means of numerical simulations using a volume-of-fluid method coupled with an adaptive mesh refinement technique. The results show that different orifice sizes induce various flow patterns, including dripping, quasijetting, quasijetting with droplet coalescence, and jetting. A predictive model is established for the extension length of the dispersed phase during the necking stage, considering orifice dimensions interplay. Furthermore, higher yield stress influences the droplet size and formation frequency by expanding the high viscosity distribution in the dispersed phase. The proposed predictive correlations for droplet size, velocity, and formation frequency, accounting for the effects of orifice dimensions and yield stress, are believed to have significant impacts on the preparation of polymeric droplets in microreactors.

Colostrum intake and neonatal characteristics in piglets experiencing varying lengths of expulsion phase

The objective of this study was to investigate how the cumulative expulsion interval, litter size, and birth order influence the characteristics of newborn piglets from hyperprolific sows, as well as their intake of colostrum. Analysis was conducted on the temporal aspects of parturition in 254 sows, including 3920 piglets. Newborn piglet characteristics examined encompassed delivery time, birth order, birth status, umbilical cord rupture, meconium staining, delivery ease, birth weight, blood oxygen saturation, and heart rate. From the raw data, colostrum intake, birth interval, and cumulative birth interval of each piglet were computed. Piglets were sorted based on the cumulative expulsion interval into nine categories: 0–30, 31–60, 61–90, 91–120, 121–150, 151–180, 181–210, 211–240, and >240 min. Litter sizes were categorized into three groups: 10–13, 14–17, and ≥18 piglets per litter. The birth-order ranking referred to the piglet's position within a litter and was categorized into four quartiles: 1, 2, 3, and 4. On average, the expulsion interval, cumulative expulsion interval, and colostrum consumption were 14.8 ± 21.8 min, 138.6 ± 155.7 min, and 407.6 ± 162.1 g, respectively. In litters with ≥18 piglets, the percentage of piglets with inadequate colostrum intake (<300 g) was higher compared to litters with 10–13 piglets (33.1 % vs. 12.9 %, P < 0.001) and 14–17 piglets (23.9 %, P < 0.001). The occurrence of stillbirths in the fourth quartile of the litter was higher than in the first (16.0 % vs. 2.2 %, P < 0.001), second (4.0 %, P < 0.001), and third (7.8 %, P < 0.001) quartiles. Among litters with ≥18 piglets, those born in the third quartile exhibited lower colostrum consumption compared to those born in the first quartile (346.0 ± 9.9 vs. 391.4 ± 8.6 g, P = 0.028). Colostrum intake decreased with longer cumulative expulsion intervals, evident from a notable decline starting at 90 min post-farrowing compared to piglets born within the first 30 min (P = 0.004). Interestingly, colostrum consumption exhibited a negative correlation with the cumulative expulsion interval (P < 0.001), but not with individual piglet expulsion intervals (P = 0.460). Piglets born with meconium staining were most prevalent among those with a cumulative expulsion interval of >240 min. In summary, both the cumulative expulsion interval and birth-order ranking significantly impact the physiological characteristics of newborn piglets and their colostrum intake. Colostrum consumption decreases and newborn piglet characteristics change with higher cumulative expulsion intervals. Identifying piglets at high risk of hypoxia and implementing appropriate treatments and management strategies within an optimal timeframe could aid pig producers in reducing pre-weaning mortality among piglets born to hyperprolific sows.

The characteristics of autolysins associated with cell separation in Bacillus subtilis.

The peptidoglycan hydrolases responsible for the cell separation of Bacillus subtilis cells are collectively referred to as autolysins. However, the role of each autolysin in the cell separation of B. subtilis is not fully understood. In this study, we constructed a series of cell separation-associated autolysin deficient strains and strains overexpressing the transcription factors SlrR and SinR, and the morphological changes of these strains in liquid culture were observed. The results showed that the absence of D,L-endopeptidases CwlS and LytF only increased the cell chain length in the early exponential phase. The absence of D,L-endopeptidase LytE or N-acetylmuramyl-L-alanine amidase LytC can cause cells to form chains throughout the growth of B. subtilis, although the cell chain length was significantly shortened during the stationary phase. However, the absence of peptidoglycan N-acetylglucosaminidase LytD only caused minor defect in cell separation. Therefore, we concluded that LytE and LytC were the major autolysins that ensure the timely separation of B. subtilis daughter cells, whereas CwlS, LytF, and LytD were the minor autolysins. In addition, overexpression of the transcription factors SinR and SlrR in the cwlS lytF lytC lytE mutant enabled B. subtilis cells to form ultra-long chains in the vegetative phase, and its biomass level was basically the same as that of the wild type. This led to the conclusion that besides inhibiting the expression of lytC and lytF, the SinR-SlrR complex also has other potential mechanisms to inhibit cell separation.IMPORTANCEIn this study, the effects of CwlS, LytC, LytD, LytF, LytE, and SinR-SlrR complex on the cell separation of Bacillus subtilis at different growth phases were studied, and an ultra-long-chained B. subtilis strain was constructed. In microbial fermentation, due to its large cell size, this ultra-long-chained B. subtilis strain may be more likely to be precipitated or intercepted during the removal of bacterial process with centrifugation and membrane filtration as the main methods, which is crucial to improve the purity of the product.

P-407 Exploring the effectiveness of tailoring estradiol supplementation duration to mimic the natural cycle length in artificial endometrial preparation for frozen embryo transfer cycles

Abstract Study question Is an estrogen supplementation duration similar in length to the follicular phase of a natural cycle associated with a better clinical pregnancy rate? Summary answer An estradiol supplementation duration, which is proportional to the natural follicular phase length, results in significantly better outcomes compared to shorter exposure durations What is known already The last decade witnessed a major increase in the use of single euploid frozen embryos. Artificial endometrial preparation (AEP) has proven to be effective to prepare the endometrium for implantation. However, several features of AEP need to be clarified mainly the duration of estrogen supplementation and until now no study took into consideration the difference between exogenous estrogen supplementation and the actual length of the follicular phase of each patient during AEP. Furthermore, most of the studies focused on upper limit of estrogen exposure while few considered the lower limit. Unfortunately, the results on pregnancy rates were mixed. Study design, size, duration 663 single euploid frozen embryo transfer cycles were included. Patients underwent vaginal ultrasound and hormonal blood measurement (Estradiol, Progesterone) on day 2 of their cycle. Estradiol valerate (4 mg the first 2 days then 6 mg daily, Orally) was started on the same day and another control was done around day 10. When triple lining pattern of the endometrium was seen, vaginal progesterone was initiated (800 mg daily) and SET was done after 120 hours. Participants/materials, setting, methods Patients with reported regular menstrual cycle (25-35 days) were included and the difference between estrogen supplementation and the actual follicular phase was calculated for each patient. Patients were sorted into 2 groups as follows: 231 women with normal interval (±2 days of follicular phase length), and 432 women with short interval (-3 days or shorter). Only the first single euploid embryo transfer cycles were analyzed for these patients. Main results and the role of chance Whereas patients had similar characteristics in both groups, the corresponding clinical pregnancy rates in normal and short supplementation groups were 69.3% (160/231) and 64% (277/432), respectively. After balancing the groups for BMI, embryo quality and endometrial thickness with inverse treatment probability weighting, those who received estradiol supplementation proportional to their natural follicular phase length had significantly higher clinical pregnancy rates compared to those who received it for shorter durations (adjusted OR: 1.48, 95% CI: 1.16 – 1.89, P = 0.002). Serum estradiol levels were available for 523 cycles, the clinical pregnancy rate in those within the 1st quartile (&amp;lt;155pmol/L), 2nd to 3rd quartile (155 to 275pmol/L) and 4th quartile (&amp;gt;275pmol/L) were 70%, 64.7% and 63%. After adjusting for BMI and embryo quality, higher (&amp;gt;275pmol/L) (adjusted OR: 0.84, 95% CI: 0.53-1.32, P = 0.442) and lower(&amp;lt;155pmol/L) (adjusted OR: 1.37, 95% CI: 0.85-2.22, P = 0.202) estradiol levels were not significantly associated with clinical pregnancy. Limitations, reasons for caution The present study could not address the influence of very long estrogen supplementation on clinical pregnancy rate due to limited samples. Further prospective studies, including larger populations, are needed to confirm our findings Wider implications of the findings Our data indicate that mimicking individually the natural cycle regarding estrogen supplementation duration in AEP for single euploid embryo transfer cycles can produce significant improvement in clinical pregnancy rates. Trial registration number not applicable

An in vitro platform for quantifying cell cycle phase lengths in primary human intestinal epithelial cells

The intestinal epithelium dynamically controls cell cycle, yet no experimental platform exists for directly analyzing cell cycle phases in non-immortalized human intestinal epithelial cells (IECs). Here, we present two reporters and a complete platform for analyzing cell cycle phases in live primary human IECs. We interrogate the transcriptional identity of IECs grown on soft collagen, develop two fluorescent cell cycle reporter IEC lines, design and 3D print a collagen press to make chamber slides for optimal imaging while supporting primary human IEC growth, live image cell cycle dynamics, then assemble a computational pipeline building upon free-to-use programs for semi-automated analysis of cell cycle phases. The PIP-FUCCI construct allows for assigning cell cycle phase from a single image of living cells, and our PIP-H2A construct allows for semi-automated direct quantification of cell cycle phase lengths using our publicly available computational pipeline. Treating PIP-FUCCI IECs with oligomycin demonstrates that inhibiting mitochondrial respiration lengthens G1 phase, and PIP-H2A cells allow us to measure that oligomycin differentially lengthens S and G2/M phases across heterogeneous IECs. These platforms provide opportunities for future studies on pharmaceutical effects on the intestinal epithelium, cell cycle regulation, and more.

MethPhaser: methylation-based long-read haplotype phasing of human genomes

The assignment of variants across haplotypes, phasing, is crucial for predicting the consequences, interaction, and inheritance of mutations and is a key step in improving our understanding of phenotype and disease. However, phasing is limited by read length and stretches of homozygosity along the genome. To overcome this limitation, we designed MethPhaser, a method that utilizes methylation signals from Oxford Nanopore Technologies to extend Single Nucleotide Variation (SNV)-based phasing. We demonstrate that haplotype-specific methylations extensively exist in Human genomes and the advent of long-read technologies enabled direct report of methylation signals. For ONT R9 and R10 cell line data, we increase the phase length N50 by 78%-151% at a phasing accuracy of 83.4-98.7% To assess the impact of tissue purity and random methylation signals due to inactivation, we also applied MethPhaser on blood samples from 4 patients, still showing improvements over SNV-only phasing. MethPhaser further improves phasing across HLA and multiple other medically relevant genes, improving our understanding of how mutations interact across multiple phenotypes. The concept of MethPhaser can also be extended to non-human diploid genomes. MethPhaser is available at https://github.com/treangenlab/methphaser.

Performance Evaluation and Degradation Analysis of Suspended Dense Broken Stone Road Foundation Stabilized by Cement under Conditions of Freezing and Thawing

A suspended dense graded broken stone road foundation stabilized by cement is a commonly employed material in roadworks, which is vulnerable to harm caused by freezing and thawing processes. This investigation intends to evaluate the laboratory behavior and the characteristics of freezing and thawing process-induced deterioration in a broken stone road foundation stabilized by cement with suspended dense grading, employing mechanical examinations and acoustical methods. The rate of mass loss in the broken stone road foundation stabilized by cement progressively rises, and the rate of decline in the compressive strength could potentially intensify as freezing and thawing processes augment. The modulus of resilience diminishes as freezing and thawing processes progress, and ultrasonic wave velocity also decreases. The patterns of mass loss, compressive strength decline, resilience modulus reduction, and ultrasonic wave velocity alteration adhere to a parabolic fitting relationship with freeze–thaw cycles, with an R2 above 0.95. The curves depicting the relationship of mass, compressive strength, resilience modulus, and ultrasonic wave velocity exhibit a steeper trend significantly after 10–15 cycles, which can be ascribed to the emergence of microcracks and the progression of flaws within the material. The evolution of damage in the broken stone road foundation stabilized by cement is monitored to progress through three distinct stages based on acoustic emission: initial, stationary, and failure. As freezing and thawing processes accumulate to 20 cycles, the length of initial phase correspondingly rises to three times, the length of failure stage diminishes to about one fifth.

Limited life‐history plasticity in marginal population of an invasive foundation species: Unraveling the genetic underpinnings and ecological implications

AbstractPlant's life history can evolve in response to variation in climate spatio‐temporally, but numerous multiple‐species studies overlook species‐specific (especially a foundation species) ecological effects and genetic underpinnings. For a species to successfully invade a region, likely to become a foundation species, life‐history variation of invasive plants exerts considerable ecological and evolutionary impacts on invaded ecosystems. We examined how an invasive foundation plant, Spartina alterniflora, varied in its life history along latitudinal gradient using a common gardens experiment. Two common gardens were located at range boundary in tropical zone and main distribution area of S. alterniflora in temperate zone in China. Within each population/garden, we measured the onset time of three successive phenological stages constituting the reproductive phase and a fitness trait. In the low‐latitude garden with higher temperature, we found that reproductive phase was advanced and its length prolonged compared to the high‐latitude garden. This could possibly due to lower plasticity of maturity time. Additionally, plasticity in the length of the reproductive phase positively related with fitness in the low‐latitude garden. Marginal population from tropic had the lowest plasticity and fitness, and the poor capacity to cope with changing environment may result in reduction of this population. These results reflected genetic divergence in life history of S. alterniflora in China. Our study provided a novel view to test the center–periphery hypothesis by integration across a plant's life history and highlighted the significance in considering evolution. Such insights can help us to understand long‐term ecological consequences of life‐history variation, with implications for plant fitness, species interaction, and ecosystem functions under climate change.

Effect of Rebozo and Birth Ball Techniques on Length of Active Phase for Primi Maternity Woman at Ayu Independent Practicing Midwife In 2023

Effect of Rebozo and Birth Ball Techniques on Length of Active Phase for Primi Maternity Woman at Ayu Independent Practicing Midwife In 2023

Is prolonged luteal phase a problem in lactating Holstein cows?

In this study, the main objective was to assess if long luteal phases could have other causes than pregnancy losses. We enrolled Holstein dairy cows ≥50 d in milk (DIM) from a commercial herd in Brazil from October 2016 to August 2017. All cows received an estradiol-based synchronization protocol, and, on the day of insemination (d 0), were randomly assigned either an artificial insemination (AI) or a placebo insemination (PBO) in a 3:1 ratio. An ultrasound was used to assess the presence of a CL on d17, 24, and 31, which, combined to the information from patches for the detection of estrus, was used to determine the length of the luteal phase following AI or PBO. Pregnancy was assessed by ultrasound on d 31 and cows that were pregnant were excluded from the analyses. The length of the estrous cycles was categorized as short (<17 d), normal (17-23 d), long (24-30 d), and very long (≥31 d). We compared the proportion of cows in each category between the AI and PBO groups using a cumulative ordinal mixed model. We define prolonged luteal phase as estrous cycles ≥24 d and tested its association with potential risk factors (parity, season, DIM, uterine size and position score, milk production, body condition score, and the presence of a corpus luteum (CL) at enrollment to the synchronization protocol) using mixed logistic regression models. Results are presented as odds ratio (OR) and 95% credible intervals (BCI). Data from 876 inseminations (AI: n = 616, PBO: n = 260) was collected. Overall, 12% of estrous cycles were short, 31% were normal, 19% were long, and 38% were very long. There was no difference in the odds of being in longer estrous cycle categories for the AI compared with the PBO group (OR = 0.92, 95% BCI = 0.76-1.10). Season and presence of a CL at enrollment were associated with prolonged luteal phase. In the AI group, there was a possible effect of early pregnancy losses on the lifespan of the CL, but not the PBO group, which led us to conclude that long and very long estrous cycles were not all caused by the embryonic loss. In fact, the high prevalence of cows with an extended CL lifespan in the present study suggests this could be an under- or miss-reported characteristic of high-producing lactating Holstein cows. This finding may have important repercussions in the understanding of the CL function physiology of lactating Holstein cows.

A comparative study of progressive failure of granite and marble rock bridges under direct shearing

Shear failure of rock bridges is an important process in geological phenomena, including landslides and earthquakes. However, the progressive failure of natural rock bridges has not yet been fully understood. In this work, we carried out direct shearing experiments on both granite and marble rock bridges, and applied acoustic emission (AE) monitoring throughout the experiments. With the mechanical curves and the evolution of AE activity (including AE energy rate and b value), the failure of rock bridges can be divided into three pre-failure phases and one ultimate failure phases. We analyzed the effects of normal stress and lithology on the pre-failure phases. We noted that with the increasing of normal stress, the length of stable cracking phase decreases and the length of unstable cracking phase slightly increases, except for marble rock bridges at high normal stress, which maintains a great proportion of stable cracking phase that possibly results from the great off-fault damage. Increasing normal stress also suppresses the dilation of granite rock bridges, but has a different effect on marble rock bridges, which also suggests the effect of lithology on failure modes.

The improvement of wear and corrosion resistance of nickel-graphite coating with modified graphite phase size

The corrosion resistance, friction and wear properties of an abradable seal coating are highly dependent on the size and distribution of lubrication phase. In this work, nickel-graphite (Ni-G) coatings were fabricated by a supersonic atmospheric plasma spraying system (SAPS) and a standard atmospheric plasma spraying system (APS), respectively. The effect of size and distribution of graphite phase on the performance of Ni-G coatings was investigated. The results suggested that the SAPS coating had an average single graphite phase area of 35.4 ± 5.1 μm2, which is approximately 35.4 % less than that of the APS coating, while the average graphite phase width and length in SAPS coating decreased by 22.2 % and 16.7 % compared to the APS coating. The fine distributed graphite phase improved the formation of structure with a small cathode and a large anode, which effectively increased the corrosion resistance of SAPS coating. The reciprocating sliding friction facilitated the creation of a uniform and uninterrupted lubricant layer, attributed to the finely dispersed graphite phase of SAPS coating. In comparison to the as-sprayed and subsequent corroded APS coatings, the friction coefficients of the SAPS coating exhibited a reduction of approximately 9.1 % and 13.3 %, respectively. The aforementioned findings showed that the small-sized graphite phase was conductive to the improvement of corrosion resistance, friction and wear properties of Ni-G abradable coatings.

Factors influencing inflammatory diseases in the bitch and the survival of her offsprings

Feeding raw meat is becoming increasingly common among dog owners. This feeding practice can pose a hygienic risk and can lead to health risks for dogs and their owners. Hygienically sound food rations, that are balanced in terms of all nutrients and energy, must be feed to breeding dogs. The aim of this study was to record the influence of raw feeding on the occurrence of mastitis, metritis and the survival of puppies. An online questionnaire was sent to kennel club registered dog breeders in Germany and Switzerland. A total of 531 litters were recorded and evaluated. Mastitis and/or metritis were present in 9,2 % and 2,8 % (n = 49 and n = 15, respectively) of the breeding bitches. 29 % (n = 154) of the breeders reported loss of puppies in the litter. The most common cause were stillbirths (n = 105 litters with 187 stillborn puppies), and/or early mortality (n = 50 litters with 73 puppies that died in the first 48 hours). The occurrence of puppy losses in the litter and/or a higher proportion of puppy losses in the litter was favored by increased body weight of the bitch in larger dog breeds, existing previous illnesses, previously reported gestation or postpartum problems, increasing length of the parturition phase and/or a cesarean section. A higher total number of surviving puppies was associated with increased weight and anamnestic reported health of the bitch and the use of milk powder instead of other milk substitutes. A relationship between raw feeding and the occurrence of mastitis, metritis, the total number of surviving puppies and/or the occurrence or proportion of pup losses in the litter and was not found in this study. However very few breeders in this cohort fed their bitches raw, which in turn was due to the random selection of breeders. Many years of breeding experience and the increasing parity of the bitch had a clearly positive influence on the health of the bitch.