Tissue-specific co-expression and in vitro heteropolymer formation of the two small Branchiostoma intermediate filament proteins A3 and B2

The two small intermediate filament (IF) proteins A3 and B2 of the cephalochordate Amphioxus were investigated. Blot overlays indicated a heterotypic interaction pattern of the recombinant proteins. While the individual proteins formed only aggregates, the stoichiometric mixture formed obligatory heteropolymeric filaments. Mutant proteins with a single cysteine residue in equivalent positions gave rise to filaments that oxidize to the disulfide-linked heterodimer, which can again form IF. Thus the A3/B2 filaments, which are expressed in the intestinal epithelium, are based on a hetero coiled coil. This keratin- like assembly process of A3 plus B2 was unexpected, since previous evolutionary tree calculations performed by two laboratories on the various Amphioxus IF proteins identified keratin I and II orthologs but left the A/B group as a separate branch. We discuss obvious evolutionary aspects of the Amphioxus IF multigene family, including the previously made observation that B1, the closest relative of B2, forms homopolymeric IF in vitro and is, like vertebrate type III proteins, expressed in mesodermally derived tissues. (C) 2002 Elsevier Science Ltd

Noise Reduction Algorithm Based on Template Wavelet Coefficients

In the paper, a new algorithm based on the application of template wavelet coefficients is proposed to solve the problems concerning noise reduction in the vicinity of edges in signals and images and suppressing parasitic oscillations, which arise when threshold wavelet algorithms are used. It is shown that this approach calls for choosing a specific wavelet. Examples of the application of the developed technique are given.В статье предложен новый алгоритм, основанный на применении шаблонных вейвлетных коэффициентов для решения проблем, связанных с удалением шума в окрестности границ в сигналах и изображениях и подавлением паразитных осцилляций, которые возникают при использовании пороговых вейвлетных алгоритмов. Показано, что этот подход требует выбора специального вейвлета. Приведены примеры применения предложенного подхода.У статті запропоновано новий алгоритм, що базується на використанні шаблонних вейвлетних коефіцієнтів для розв’язання проблем, пов’язаних з видаленням шуму поблизу меж в сигналах та зображеннях і знищення паразитних осциляцій, що виникають у разі застосування порогових вейвлетних алгоритмів. Зазначено, що цей підхід вимагає вибору спеціального вейвлета. Наведено приклади використання запропонованого підходу

Clinotron: a Promising Source for THz Regions

Potentials of the backward-wave oscillator (BWO) with an inclined electron beam (the clinotron) as a source of electromagnetic radiation in THz regions are examined. A self-consistent collective electron-wave interaction theory is developed to study starting conditions and steady state oscillations of clinotron tubes. Optimization of the geometry of pulsed and continuous wave (CW) 1-THz clinotrons is carried out and a possibility of the development of promising tubes for this frequency region is found.Рассмотрены перспективы использования лампы обратной волны с наклонённым электронным пучком (клинотрона) как источника электромагнитного излучения терагерцевого диапазона частот. Для изучения пусковых условий и стационарных колебаний клинотрона разработана самосогласованная теория коллективного взаимодействия электронов с волной. Обнаружена возможность разработки перспективных ламп для терагерцевого диапазона частот и проведена оптимизация геометрии клинотронов импульсного и непрерывного действия с частотой генерации 1 ТГц.Розглянуто перспективи використання лампи зворотної хвилі з нахиленим електронним пучком (клінотрона) як джерела електромагнітного випромінювання терагерцевого діапазону частот. Для вивчення пускових умов та стаціонарних коливань клінотрона розроблено самоузгоджену теорію колективної взаємодії електронів з хвилею. Виявлено можливість розробки перспективних ламп для терагерцевого діапазону частот и проведено оптимізацію геометрії клінотронів імпульсної та безперервної дії з частотою генерації 1 ТГц

Prediction of parturition in Holstein dairy cattle using electronic data loggers

The objective of the present study was to assess the effect of parturition on behavioral activity [steps, standing time, lying time, lying bouts (LB), and duration of LB] 4 d before calving using electronic data loggers. Animals (n = 132) from 3 herds were housed in similar freestall barns using a prepartum pen 21 d before the expected calving date and were moved into a contiguous individual maternity pen for parturition. Electronic data loggers were placed on a hind leg of prepartum heifers (heifers, n = 33) and cows (cows, n = 99) at 7 ± 3 d before the expected calving date and removed at 14 ± 3 d in milk. Calving ease (scale 1–4), parity, calving date and time, and stillbirth (born dead or died within 24 h) were recorded. The number of steps (no./d), standing time (min/d), lying time (min/d), number of LB (no./d), and duration of LB (min/b) were recorded. Data were analyzed using MIXED procedures of SAS, adjusting for the herd effect. Only cows experiencing unassisted births (calving ease = 1) were included in the study. An activity index was developed to predict calving time. Heifers and cows with unassisted births had significantly higher number of steps and longer standing time, decreased lying time, and more LB of shorter duration 24 h before calving compared with d −4, −3, and −2. Additionally, the number of LB increased as both heifers and cows approached labor starting on d −2 and peaked at the day of calving. The time since the activity index increased over 50% to parturition did not differ between heifers and cows, and the activity index revealed the shift in activity on average 6 h 14 min (range from 2 h to 14 h 15 min) before calf birth. This study provided evidence that heifers and cows approaching parturition showed a similar, but distinct, behavioral pattern that can be observed on average 6 h before calf birth. The potential benefits of electronic data loggers as predictors of parturition along with proactive management practices should improve the overall survival and welfare of both the dam and calf

Mycobacterium leprae genomes from a British medieval leprosy hospital: towards understanding an ancient epidemic.

BACKGROUND: Leprosy has afflicted humankind throughout history leaving evidence in both early texts and the archaeological record. In Britain, leprosy was widespread throughout the Middle Ages until its gradual and unexplained decline between the 14th and 16th centuries. The nature of this ancient endemic leprosy and its relationship to modern strains is only partly understood. Modern leprosy strains are currently divided into 5 phylogenetic groups, types 0 to 4, each with strong geographical links. Until recently, European strains, both ancient and modern, were thought to be exclusively type 3 strains. However, evidence for type 2 strains, a group normally associated with Central Asia and the Middle East, has recently been found in archaeological samples in Scandinavia and from two skeletons from the medieval leprosy hospital (or leprosarium) of St Mary Magdalen, near Winchester, England. RESULTS: Here we report the genotypic analysis and whole genome sequencing of two further ancient M. leprae genomes extracted from the remains of two individuals, Sk14 and Sk27, that were excavated from 10th-12th century burials at the leprosarium of St Mary Magdalen. DNA was extracted from the surfaces of bones showing osteological signs of leprosy. Known M. leprae polymorphisms were PCR amplified and Sanger sequenced, while draft genomes were generated by enriching for M. leprae DNA, and Illumina sequencing. SNP-typing and phylogenetic analysis of the draft genomes placed both of these ancient strains in the conserved type 2 group, with very few novel SNPs compared to other ancient or modern strains. CONCLUSIONS: The genomes of the two newly sequenced M. leprae strains group firmly with other type 2F strains. Moreover, the M. leprae strain most closely related to one of the strains, Sk14, in the worldwide phylogeny is a contemporaneous ancient St Magdalen skeleton, vividly illustrating the epidemic and clonal nature of leprosy at this site. The prevalence of these type 2 strains indicates that type 2F strains, in contrast to later European and associated North American type 3 isolates, may have been the co-dominant or even the predominant genotype at this location during the 11th century

Effect of milk cessation method at dry-off on behavioral activity of dairy cows

Drying cows off at the end of lactation is a routine management practice in dairy operations. Most dairies in the United States and many other countries dry cows off abruptly (e.g., stop milking cows on a set day), which has been shown to affect cow comfort. Gradually reducing milk production is another approach to dry cows off, routinely used in some countries and herds. The objective of the study was to evaluate the effects of abrupt and gradual milk cessation and milk yield at the time on cow activity after dry-off. Daily lying time, number of lying bouts per day, average lying bout length, and steps taken per day by abruptly and gradually dried-off cows were monitored by data loggers for 2 wk before and after the final milking at the end of lactation. Gradual cows were milked once daily for the last week of lactation, and abrupt cows were milked as usual (3 x /d) until the end of lactation. Gradual cessation of milking significantly reduced milk yield by the day of dry-off. After dry-off, gradual cows tended to have longer lying bouts than abrupt cows, but no other differences in cow activity between the 2 treatments were observed. Regardless of the dry-off method, the average length of a lying bout decreased by 4 min and total daily lying time decreased by 19 min after dry-off for each 5-kg increase in milk yield before dry-off. Lying behavior of primiparous cows was more affected by the level of milk yield at dry-off than that of older cows. A reduction in lying times with increasing milk yield may indicate discomfort due to the accumulating milk in the udder. Using a method that lowers milk production before dry-off and managing primiparous and multiparous cows separately around dry-off are beneficial for cow comfort after dry-off.Peer reviewe