Half Of January Research Articles

Arctic Stratosphere Dynamical Processes in the Winter 2021–2022

The Arctic stratosphere winter season of 2021–2022 was characterized by a stable, cold stratospheric polar vortex with a volume of polar stratospheric clouds (PSC) close to the maximum values since 1980, before the beginning of minor sudden stratospheric warming (SSW) events in the late February and early March and major SSW on 20 March. Analysis of dynamical processes of the Arctic stratosphere using reanalysis data indicates that the main reasons for the strengthening of the stratospheric polar vortex in January–February are the minimum propagation of planetary wave activity from the troposphere to the stratosphere over the past 40 years and its reflection in the upper stratosphere–lower mesosphere in the second half of January. The first minor SSW was limited to the upper polar stratosphere, whereas the second one propagated to the middle and lower stratosphere and led to the disappearance of the PSC, which prevented significant ozone depletion. Both minor and major SSW events led to a weakening of the residual meridional circulation in the upper Arctic stratosphere and its intensification in the middle and lower stratosphere, which contributed to additional warming of the subpolar region and weakening of the polar vortex.

Optimal Period for Winter Mountain Tourism in Romania

Observations in Romania show that the months of January and February are starting to show an increasing interest for tourists in areas known for winter sports involving snow. This observation is at odds with the period hitherto considered traditional for winter tourism in Romania, i.e., from the end of December to the first few days of January, when school holidays and employee holidays are frequently scheduled. Analysis of the climatic data of recent years shows a shortening of the period when natural weather conditions are favorable for this type of tourism. In this paper it was statistically determined that the maximum share of negative temperature coverage of Romania’s territory tends to occur at present in the second half of January. It is therefore necessary to correlate the school and labor law timetables with the new climatic conditions and other measures to adapt to current conditions.

Is gold favourable than bitcoin during the COVID-19 outbreak? Comparative analysis through wavelet approach

The novel coronavirus (COVID-19) has tremendously oscillated the global financial markets. Consequently, investors feel pressured to find safe-haven investments during the pandemic crisis. Numerous studies have evaluated bitcoin's safe-haven properties during the COVID-19; however, the present study considered gold as a potential safe-haven for investors of renowned stock markets of Asia, Europe, and the US. The present investigation computed the ratio of gold to bitcoin (Gold_Bitcoin) and compared the safe-haven properties of gold in contrast to bitcoin. The present study analysed the Morlet Wavelet approach and found that most of the time during the COVID-19, gold investments proved to be more beneficial than bitcoin. Remarkably, the findings highlighted that the Gold_Bitcoin ratio increased in higher and lower frequencies combined with CAC40. In the long run, the return on investments in gold increased in contrast to bitcoin returns pooled with DAX30. Also, the Gold_Bitcoin ratio of the US stock market increased during the one-week and one-month cycles of January and August. Likewise, the Hang Seng Index caused the Gold_Bitcoin ratio to rise at a much higher frequency (i.e., the second half of January, the first half of February and April, and the first half of June and August), whereas IBEX35 surged Gold_Bitcoin at a lower frequency (i.e., during January, February, and August). In higher frequency bands, LSE increased the Gold_Bitcoin ratio (i.e., in February and March); nevertheless, Gold_Bitcoin showed a positive connection with FTSEMIB in the one-to-two month's frequency band (i.e., throughout January, February, and August). Interestingly, the returns on the Gold_Bitcoin ratio increased in the SSEC stock market in the high-frequency band (i.e., during March, May, and July 2020).

Exploring species composition and population dynamics of thrips (Thysanoptera: Thripidae) in peanut crops in Argentina

Thrips (Thysanoptera: Thripidae) are major pests of peanut (Arachis hypogaea L.). They cause feeding damage and indirect injuries transmitting plant viruses. In Argentina, peanut is commonly affected by thrips. The crop also is infected by groundnut ringspot orthotospovirus, a virus transmitted by thrips vectors. However, in the country, information about thrips in peanut is very scarce. A 3-yr study was conducted to characterize the species composition and thrips population dynamics in the main peanut-producing area in Argentina. Frankliniella schultzei (Trybom), followed by Caliothrips phaseoli (Hood) were the most abundant species. Together the two species accounted for ~ 95-99 % of the total adult thrips captured in each season. Significant different abundances were observed among these two thrips species throughout each peanut growing season. Nevertheless, the temporal dynamics of F. schultzei and C. phaseoli showed a similar trend in the three study years. In general, the colonization by F. schultzei started in late December and their population increased from the second half of January peaking around the first half of February. The highest densities of F. schultzei occurred simultaneously in foliage and flowers during the warmer months of the year. The C. phaseoli population inhabited on foliage and peaked in late February or mid-March. Other species collected were Frankliniella occidentalis (Pergande), Frankliniella gemina Bagnall, and Thrips tabaci (Lindeman). This study mentions F. gemina in peanut for the first time. Results show that F. schultzei and C. phaseoli are common thrips pests in peanut in Argentina and provide new information about the population dynamics of these thrips species in peanut crops.

Black Carbon Emission Reduction Due to COVID-19 Lockdown in China.

During the Lunar New Year Holiday of 2020, China implemented an unprecedented lockdown to fight the COVID‐19 outbreak, which strongly affected the anthropogenic emissions. We utilized elemental carbon observations (equivalent to black carbon, BC) from 42 sites and performed inverse modeling to determine the impact of the lockdown on the weekly BC emissions and quantify the effect of the stagnant conditions on BC observations in densely populated eastern and northern China. BC emissions declined 70% (eastern China) and 48% (northern China) compared to the first half of January. In northern China, under the stagnant conditions of the first week of the lockdown, the observed BC concentrations rose unexpectedly (29%) even though the BC emissions fell. The emissions declined substantially thereafter until a week after the lockdown ended. On the contrary, in eastern China, BC emissions dropped sharply in the first week and recovered synchronously with the end of the lockdown.

Vulnerability of a top marine predator to coastal storms: a relationship between hydrodynamic drivers and stranding rates of newborn pinnipeds

Coastal storms have increased in recent decades, affecting many species, including the South American sea lion (Otaria byronia). Reports of stranded sea lion pups are becoming common in Chile, presumably due to the increase in the frequency and intensity of coastal storms. To validate this assumption, a 10-year database was built by coupling wave generation and coastal propagation models to correlate pure wave parameters (significant wave height Hs, peak period Tp, normalized wave power Hs2 Tp) and wave parameters including the tidal level (maximum surface elevation η, modified wave power η2 Tp) with records of stranded pups in Cobquecura, the largest breeding colony in central Chile. The correlation between the number of pups stranded per day and wave parameters in the first half of January and the last half of February is poor, while they are stronger for the second half of January and the first half of February. The higher number of stranded pups coincide with coastal storms with normalized wave power values exceeding a threshold of 100 m2/s. Conversely, below this threshold there is wide dispersion between the number of strandings and wave parameters. Identifying wave parameter thresholds could be used to predict when newborn pups will be most affected by coastal storms, and thus help institutions to develop remediation techniques for animals at risk.

Daily rainfall erosivity as an indicator for natural disasters: assessment in mountainous regions of southeastern Brazil

Rainfall erosivity is defined as the rainfall potential to cause erosion. Its concept is based on the kinetic energy of rainfall, rainfall intensity, and maximum rainfall intensity in a 30-min period, and purposes recurrence analyzes involving soil losses. It is a climatic index related to damages caused by erosion, landslides, and flooding. This study sought to: (1) model daily rainfall erosivity in Mantiqueira Range Region (MRR), Southeastern Brazil; and (2) propose the Rmaxday as an indicator of the areas prone to natural disasters. Rmaxday is defined as the maximum daily rainfall erosivity and is determined from the maximum daily rainfall. It should be calculated from a historical series over the least 22 years. Three seasonal models were fitted using observed historical series. The models exhibited consistent statistical performances (CNS = 0.55, on average), thereby indicating that they can be used for further studies regarding natural disasters in the MRR. The Center to Northeastern MRR had the most vulnerable areas, as they experienced Rmaxday values > 1600 MJ ha−1 mm h−1 in the year of 2000 when fatalities were registered. Overall, the first half of January had the greatest Rmaxday in MRR. This period has been the most relevant for provoking natural disasters caused by heavy rainfall in MRR. Rmaxday is a promising indicator to identify areas prone to natural disasters, as it is more robust than the commonly used rainfall depth intervals, i.e., there is a relationship between its magnitude and the damages provoked by natural disasters.

Quantifying the improvement in confirmation efficiency of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the early phase of the outbreak in Hong Kong in 2020

BackgroundsThe emerging virus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), caused a large outbreak of coronavirus disease, COVID-19, in Wuhan, China, since December 2019. COVID-19 soon spread to other regions of China and overseas. In Hong Kong, local mitigation measures were implemented since the first imported case was confirmed on January 23, 2020. Here we evaluated the temporal variation of detection delay from symptoms onset to laboratory confirmation of SARS-CoV-2 in Hong Kong. MethodsA regression model is adopted to quantify the association between the SARS-CoV-2 detection delay and calendar time. The association is tested and further validated by a Cox proportional hazard model. FindingsThe estimated median detection delay was 9.5 days (95%CI: 6.5−11.5) in the second half of January, reduced to 6.0 days (95%CI: 5.5−9.5) in the first half of February 2020. We estimate that SARS-CoV-2 detection efficiency improved at a daily rate of 5.40% (95%CI: 2.54−8.33) in Hong Kong. ConclusionsThe detection efficiency of SARS-CoV-2 was likely being improved substantially in Hong Kong since the first imported case was detected. Sustaining enforcement in timely detection and other effective control measures are recommended to prevent the SARS-CoV-2 infection.

Alder pollen season in selected cities of Poland in 2020

This paper presents the course of alder pollination season in Poland in 2020. The measurements were performed in Bydgoszcz, Bialystok, Lublin, Olsztyn, Opole, Piotrkow Trybunalski, Sosnowiec, Szczecin, Warsaw, Wroclaw and Zielona Gora. Volumetric method with the use of Volumetric Spore Trap (Burkard, Lanzoni) was implemented. Pollen season was defined as the period in which 95% of the annual total catch occurred. The alder pollen season in 2020 started about 10–30 days earlier compared to 2017–2019. The pollen season started first in Szczecin, Opole and Zielona Gora (in the second half of January). In the other cities alder pollen season started in first half of February. The highest daily pollen count was recorded in Lublin (1211 P/m3). In other cities the maximum concentrations ranged from 160 P/m3 in Sosnowiec to 465 P/m3 in Piotrkow Trybunalski. The highest alder pollen concentrations were detected in the first decade of March (March 1st–3rd). Only in Zielona Gora, Wroclaw, Opole and Sosnowiec the maximum concentration was recorded in the third decade of February. The annual pollen sum of Alnus in 2020 was even 5–10 times lower than in years 2019.

Dynamics of Numbers and Occurrence of Colonial Species of Birds in the Area of Ukrainian Antarctic Station Akademik Vernadsky

Abstract The research covers water area, island archipelagos and coastal line of the Antarctic Peninsula from 65°31ʹ S, 64°25ʹ W in the South to 65°03ʹ S, 63°53ʹ W in the North. There was time gap of 7 years between the researches (2011 and 2018), which allows to define tendencies in development of individual colonies and to make conclusion about success of existence of a given species. The work itself was carried out during the first half of January, that is in the time when the stage of brooding ends and the period of hatching starts. As of 2011, 12 nesting points of gentoo penguin (Pygoscelis papua) with total number of 8,342 pairs were found in the region under investigation. Till 2018, quantity of the colony grew to 14, with total number of 14,105 pairs. For seven years, quantity of nesting points of aelie penguin (Pygoscelis adeliae) almost did not change (4 colonies). Instead, total number of the species decreased somewhat: from 3559 pairsin 2011 to 3295 onesin 2018. Number of chinstrap penguin (Pygoscelis antarctica) in united stable locality for nesting also decreased from 26 pairsin 2011 to19 onesin 2018. Booth Island (65°04ʹ S, 64°02ʹ W) for chinstrap penguins and Green Island (65°19ʹ S, 64°09ʹ W) for gentoo penguins are the southern most points of nesting range of the species. Also, 7 colonies of antarctic shag (Phalacrocorax bransfieldensis) were revealed in the region under investigation. For seven years from 2011 to 2018 total number of the species in the region under investigation grew from 190 pairs to 299, and in most cases the antarctics shag forms settlements jointly with penguins.

Breeding biology of the Helmeted Manakin Antilophia galeata in an ecotone between the Atlantic Forest and the Cerrado

Manakins (Pipridae) are well-known by their promiscuous mating system. Nonetheless, scarce evidence suggests that the Helmeted Manakin Antilophia galeata, the only dichromatic manakin widely distributed in the South American Cerrado, is monogamic. We studied the breeding biology of the Helmeted Manakin in the state of Minas Gerais, southeastern Brazil. We found 17 nests, which are built in the forest undergrowth (usually below 3 m height). Nests are a cup attached by its top lip usually in the angle of a forked branch. The nest attachment zone is made mostly of spider silk. The structural zone is constructed with dry broad leaves, leaf petioles and horsehair fungus, which were bind together by a considerable amount of spider silk. The outer (decorative) zone is made with some hanging dry broad leaves, frequently forming a tail. Clutch size is always two (n = 12), and eggs are long oval, with a ground color in different shades of beige, marked with irregular spot, blotches and, sometimes, streaks ranging from light to dark brown. Mean eggs measurements were 23.9 x 16.3 mm (n = 14), weighting 3.3 g (n = 10). Eggs are laid once each day and hatching is synchronous. Females are the sole responsible for nest building (which usually took 10 days), incubation (18.5 days), and nestling care (18.3 days). The simple percentage of successful nests (n = 11) was 27% and predation was the main cause of nest failure. The breeding season extends from the second half of August to the first half of January. Renesting after loss of a first clutch is a common strategy and we recorded up to three nesting attempts for a single female. We present evidence that the Helmeted Manakin is promiscuous, as usual for a dichromatic manakin.

Dynamics of flowering of male and female inflorescence and pollen germination of hazel in the conditions of the Banja Luka region

Studying the hazel flowering was carried out in agro-ecological conditions of the Banja Luka in the period from December to March during 2010/2011 and 2011/2012. The study was conducted on 13 hazel cultivars in two orchards. In the first orchard, the following four cultivars were observed: ‘Tankoljuskasti’, ‘Multiflora’, ‘Merveille de Bollwiller’and ‘Tonda Gentile Romana’, whilst the second orchard included the following: ‘Hall’s Giant’, ‘Gustav’s Zellernuss’, ‘Istrian Round’, ‘Avellana’, ‘Romai’, ‘Apolda’, ‘Ludolph’s Zellernuss’, ‘Imperiale de Trebizonde’and ‘Jean’s’. Phenological observations of the development of flowering phenophase with the aforementioned cultivars were monitored every three days in both years. In 2010/2011 the blooming of male and female inflorescence of the observed hazel cultivars lasted from late December to mid-March in total. The presence and pollen germination was proven to be a limiting factor for a successful pollination and fruit set in 2011. Namely, the pollen of cultivars: ‘Hall’s Giant’, ‘Istrian Round’, ‘Ludolph’s Zellernuss’, ‘Avellana’, ‘Imperiale de Trebizonde’ and ‘Romai’ did not germinate, and with ‘Gustav’s Zellernuss’, pollen germination was very low (7,22%). In ‘Apolda’, ‘Jean’s’, ‘Merveille de Bollwiller’, ‘Tonda Gentile Romana’, ‘Multiflora’ and ‘Tankoljuskasti’ pollen germination ranged between 28,57-81,69%. In 2011/2012 the flowering of male and female inflorescence of the observed hazel cultivars started 30 to 45 days later than the previous year i.e., female inflorescence of all the observed cultivars bloomed in early and mid-March, except in ‘Tankoljuskasti’, in which female inflorescence bloomed in late January and early February. Male inflorescence of ‘Tankoljuskasti’, ‘Hall’s Giant’ and ‘Gustav’s Zellernuss’ bloomed in the second half of January and early February, and in all other cultivars in mid-March. Pollen germination in 2012 proved to be a limiting factor for ‘Apolda’ and ‘Romai’, as their pollen did not germinate, as well as for ‘Hall’s Giant’ and ‘Jean’s’ where pollen germination was below 5%. For other cultivars, pollen germination was very good and ranged from 37,24 (‘Merveille de Bollwiller’) to 73,97% (‘Multiflora’). Based on the analysis of dynamics of blooming and pollen germination of 13 hazel cultivars in two years, the monitoring of pollen germination and strategy of artificial pollination must be adopted as a basic approach to control hazel fertility in the conditions of the Banja Luka region.

ОБРАЗОТВОРЧЕ МИСТЕЦТВО У ПОВСЯКДЕННІ СТУДЕНТІВ УНІВЕРСИТЕТУ СВ. ВОЛОДИМИРА В КОНТЕКСТІ ХУДОЖНЬОГО ЖИТТЯ КИЄВА ТА ДОВКОЛИШНЬОГО РЕГІОНУ (1834-1863)

Research works devoted to the students of St. Vladimir University usually highlight either specific features of the educational process or some aspects of their everyday life. Student‘s artistic interest has been studied to the lesser extent. The article depicts the place of fine arts in the life of the St. Vladimir University students in the years 1834-1863. The author points out that the students’ interest in fine arts developed under the influence of the region’s artistic tradition. Therefore, specifics of the artistic life in Ukraine is analyzed in the article as well. Special attention is paid to Kyiv as the center of artistic life of the region. Kyiv Сontract Fair which took place annually in the second half of January was the main event for the regional art market. Famous local artists worked in Kyiv and in the region as drawing teachers in various educational institutions. Other artists came to Kyiv to make drawings of its views and historical monuments. St. Vladimir University played an important role in artistic life of the city during the years 1834-1863. The University’s collection of fine arts, which included a lot of pieces of the Western European art, was designed to promote aesthetic and artistic development of the St. Vladimir University students. The University allowed students to attend elective drawing lessons provided by experienced artists and teachers. Nevertheless, only a few students attended these lessons. Scientific illustration as a component of visual art played important role in students‘ education, especially for medical students, botanists, zoologists etc. In many cases illustration was the main source of visual information for students. The author admits that a lot of students were skilled drawers themselves because drawing was the easiest way to visualize the results of their research work. Some students gathered their own small collections of art works. The fact that the students were familiar with the works of fine art affirms their high cultural level and belonging to the social elite.

The spatiotemporal patterns of sea ice in the Bohai Sea during the winter seasons of 2000–2016

ABSTRACTIn this study, sea ice thickness (SIT) and sea ice extent (SIE) in the Bohai Sea from 2000 to 2016 were investigated. A surface heat balance equation was applied to calculate SIT using ice surface temperatures estimated from the Moderate Resolution Imaging Spectroradiometer (MODIS) data with input from air temperature and wind speed from reanalyzing weather data. No trend was found in SIT during 2000–2016. The mean SIT and SIE during this period were 5.58±0.86 cm and 23×103±8×103 km2, respectively. The largest SIT and SIE periods were observed during the second half of January and the first half of February, respectively. The Spearman correlation coefficient between mean ice thickness and average air temperature from 21 automatic weather stations around the Bohai Sea was –0.94 (P < .005), and the coefficient between median ice extent and negative accumulated temperature was –0.503 (P < .001). The rate of increase in air temperature around the Bohai Sea is 0.271°C per decade in winter for 1979–2016 (P < .05), which is much lower than that in northern polar area (0.648°C per decade). This rate has not resulted in a decreasing trend in SIT and SIE for the past 16 years in the Bohai Sea.

NEW DATA ON FISH COREGONUS PELED (GMELIN,1788) IN SOME WATERBODIES OF MONGOLIA

In connection with the planned establishment of a coregonid fishery and the construction of a specialized hatchery in the area of Western Mongolia was organized with the task of studying some parts of the reproduction biology of Coregonus peled population inhabiting Lake Ulaagchnii Khar Nuur (Zavhan aimag). This species was introduced into this Mongolian lake, originally lacking any fish stock, in 1980 -1982. The samples of 11230 fish examined was collected during 1993 -1999, 2005-2011 and consisted partly of the fish originating from imported and introduced larvae and partly of the individuals belonging about 25th generating , already born in the lake studied. Most of parameters studied, such as absolute size, weight, the population dynamics, reproduction biology, of food analyses, and fatnes observed to the during vegetation period (November – December and first half of January), when the minimum daily waters temperature drops to 40centigrade or less. The sex ratio is fairly balanced if the total material from all fishings is considered. During this period of peak-spawning females predominate. The average individual standard length of spawners was 400 mm in males and 420 mm in females, the average weight 700 g in males and 900 g in females. Nevertheless, all parameters under study tend slightly to deteriorate in the course of time, which is obviously a result of the gradually increasing population density and of decreasing quantity of food available in the lake. In Khuisiin Naiman Nuur (Uburchangajskij ajmag) sexually mature at the age of 2 + , exceptionally already at the age of 1 + , at the minimum total length of 323 mm and minimum weight 295 g. Gonadosomatic index of mature females ranged 9.0 to 25.0 %, mean absolute fecundity averaged 58.060 eggs.

Detecting soil temperature trends in Northeast Iran from 1993 to 2016

Soil temperature is a fundamental agrometeorological variable which has a measureable influence on the development of plants. A comprehensive analysis of daily soil temperature trends at predetermined depths can provide a quantitative understanding for the sustainable management of agricultural systems, such as mitigating the adverse effects of anticipated temperature stress, supporting confidence levels of ideal seed sowing dates, as well as irrigation treatment durations and intervals. In this paper, daily soil temperature trends were analyzed (using the Mann-Kendall test) at depths of 5, 10, 20, 30, 50 and 100cm at seven discrete meteorological stations located throughout northeastern Iran during a consecutive period from 1993 to 2016. The results of this research indicate that in most of the study stations there exists a non-significant negative trend in soil temperature in the first half of January and also in the second half of December; these trends become significant as the soil gets deeper. For the warmer months of the year, especially from April to the end of August, soil temperature trends are positive and significant (or near significant) and these positive trends are of greater significance with a corresponding increase in soil depth. Agri-environmental agencies and practitioners may benefit from the approach used in this research (i.e. using the Mann-Kendall test to analyze trends in daily soil temperature time series) since it is an easily transferable approach that can provide a comprehensive geospatial and temporal analysis of crop and plant patterns in different regions and environmental conditions. Additionally, farmers may use daily soil temperature trends as a means to encourage the protection and mitigation of a variety of projected environmental stresses, such as water scarcity, irrigation demands, seasonal temperature fluctuations, and redundant crop rotation.

The artistic interests of St. Vladimir University students: Theatre (1834-1863)

Research works devoted to the students of St . Vladimir University usually highlight either specific features of the educational process or some aspects of their everyday life. Student‘s artistic interest has been studied to the lesser extent . The article depicts the place of theatre in the life of St . Vladimir University students in the years 1834-1863. The author points out that the interest to the theat re developed under the influence of the region’s artistic tradition. Therefore specifics of Right- and Left-bank Ukraine’s theatr ical life is analyzed in the article as well . Special attention i s paid to Kyiv as the centre of theatric al life of the region. Performances in Kyiv theatre sustained a romantic tradition. The nobles were the main spectators of the Kyiv theatre. The peak of the theatrical season in Kyiv fell on the period of Сontract Fair which took place annually in the second half of January. Students were a part of the the city's theatre audience. It was an important part of their leisure. The students patterned after popular trends in the theatrical life of Kyiv in their amateur performances. Initially, they performed in their apartments. Afterwards, in the 1850's students started to play in the University ’s hall and on the stage of the city theatre. Entrance to the student performances required a fee . The student actors received significant profits for their performances which were spent for the needs of the poorest fellows. The performances favoured the consolidation of the student corporation in the first half of the 1850’s. Soon afterward s the students’ theat re revealed a national divisions among students of Saint Vladimir University. Polish students were especially active. At the same time, participation in performances was a demonstration of the students ’ self-expression and one of the ways to become popular among their colleagues and the public. Key words: students, St. Vladimir University, theatre

Frost hardiness of flower buds of three plum (Prunus domestica L.) cultivars

Frost hardiness of flower buds of three plum (Prunus domestica L.) cultivars (‘Cacanska lepotica’, ‘Stanley’, ‘Besztercei’) was characterised by the LT50 values calculated from artificial freezing experiments conducted during eight dormancy periods between 2004 and 2016. Of the two variance components, the year effect was the strongest at the beginning of dormancy explaining around 60% of the phenotypic variation in LT50 values, while the effect of genotype started to increase from November and reached its maximum in the middle of January, when 81.2% of the variance in LT50 was due to the genotype. During the first part of winter the frost hardiness of the overwintering organs developed gradually in parallel to the decreasing ambient temperature. Flower buds were the most frost tolerant in the first half of January, when the maximum LT50 of ‘Cacanska lepotica’ was −22.8°C, for ‘Stanley’ −24.8°C and for ‘Besztercei’ it was −26.5°C, averaged over the 8 dormancy periods. From the end of dormancy the effect of year became much stronger over the genotypic differences from the second half of January. Milder days during this period resulted in faster flower bud development paralleled by a steeper and quicker decline in frost tolerance, which may significantly increase the probability of frost damages in flowers caused by late winter and spring frosts.

Twig pre-harvest temperature significantly influences effective cryopreservation of Vaccinium dormant buds

Cryopreservation of temperate woody-plant material by dormant buds is less expensive than using shoot tips isolated from tissue cultured plants; however currently, dormant buds are used only for preservation of selected temperate tree and shrub species. Using dormant buds could be an efficient strategy for long-term preservation of blueberry (Vaccinium L.) genetic resources. In this study, viability of V. hybrid ‘Northsky’ (PI 554943) dormant buds was evaluated at 30 harvest dates over three consecutive fall/winter seasons to determine the optimal harvest time that promotes high post cryopreservation viability. Twigs with dormant buds were cut into 70 mm segments containing at least two nodes, desiccated, slowly cooled, stored in liquid nitrogen vapor and tested for post-cryopreservation regrowth. The highest regrowth of cryopreserved dormant buds was observed for buds harvested in mid-December and during the first half of January. Pearson's correlation coefficients were computed to evaluate the association between bud characteristics and viability at harvest date and logistic regression models were fit to test the ability of twig characteristics and temperatures to predict post cryopreservation bud viability. Post-cryopreservation viability was negatively correlated (p < 0.05) with average minimum, maximum and daily mean temperature preceding the bud harvest but was not correlated with the dormant bud initial and end moisture content, twig diameter, the number of dormant buds/cm of twig length and the number of days in desiccation. Regression tree analysis suggested post-cryopreservation viability to be between 52 and 80% for dormant buds harvested after a 10 day average maximum air temperature of <11.2 °C. Pre-harvest air temperature was a significant indicator of optimal dormant bud harvest time to produce adequate viability for long term preservation of blueberry genetic resources.

Negative risk of cold on lag 0 day in distributed lag pattern can be due to preceding mortality peak before the temperature trough

Introduction One of the puzzling results of the distributed lag pattern of the temperature-mortality relation has been that the lag 0 risk of cold temperature range was negative in many of the locations including London and Japanese cities. Here, through simulation, we tried to show that this puzzling phenomenon can be due to time difference between mortality peak and temperature trough on this puzzling phenomenon. Methods We set the annual mortality pattern as follows: The baseline mortality follows Poisson distribution with the mean 150; the additional seasonal deaths are from 0 for July and August up to 20 for January and February; to see the offset results, we added 30 deaths to the latter half of January. We set the temperature (degC) gradient is as follows: 30 for July and August down to 5 for January and February. I added random variation for each day using normal distribution of mean 0 and sd 3. To see the offset results, we set additional deaths to be 50 during the latter half of January and set the temperature of early February to be -5. With and without the offset, we evaluated the lag patterns using distributed lag non-linear model. Results Without temperature trough- mortality peak offset, we observed no negative cold risk on lag 0 day but did observe negative cold risk on lag 0 day with the offset Conclusions The results of this simulation suggests that the preceding mortality peak before the temperature trough can create the negative cold risk on lag 0 day. Other factors inherent with the model or package, such as length of lag, degree of freedoms for the non-linear regression, should also be considered, but this simulation clearly shows that the offset created the pattern. Acknowledgements This study was supported by the Environment Research and Technology Development Fund (S-10 &amp; S14) of the Ministry of the Environment, Japan and by the Global Research Laboratory (grant K21004000001-10A0500-00710) through the National Research Foundation of Korea.